How Effective are Trump Primary Endorsements?

Unlike previous presidents, Donald Trump has made many endorsements in primary elections.  How much impact did they have?

Previous presidents rarely endorsed in contested primary elections.  This may have been because they wanted to be seen as 'above petty politics'.  Or perhaps they didn't want to risk their endorsee losing, which would weaken their political standing.

However, presidents have ways to intervene in primaries besides making endorsements.  They can help to raise money, round up endorsements by other party leaders, or instruct the party apparatus to support a candidate.  Previous presidents have relied more heavily on subtle means like these.  President Trump has had less control of the party establishment, but a stronger connection to the grassroots.  This likely explains his heavier reliance on endorsements to influence the Republican party.

METHODOLOGY

Ballotpedia has a convenient list of Trump's endorsements, from which the list in this article is adapted.

Endorsements by Donald Trump

This article is concerned with endorsements of a single candidate in Republican primaries (including jungle primaries).  I eliminated  WI-SC (nonpartisan) and the multi-candidate endorsements in WV-Senate and LA-Governor.  I added NB-Senate, which was misplaced on Ballotpedia's list.  I am not interested in general election endorsements, where the impact of a partisan endorser is likely to be negligible.

My methodology is to look at public polling and election results before and after Trump endorsed, and see whether there was a change.  If Trump's endorsement had an impact, the endorsee's number should improve, whether immediately or over time.

There are various limitations to this methodology.  Polling has both a theoretical margin of error, and practical difficulties finding a representative sample.  Nonetheless, it is still useful for observing trends.

We should also note that the effect of endorsement will vary from race to race.  Primary electorates in some districts are more friendly to Trump than others.  Endorsements generally have more impact when candidates are less known, which generally includes open seats.

RACES WITH INCUMBENTS

I separated the races with R incumbents into endorsements of incumbents and endorsements against incumbents.  The latter category was split into controversial and uncontroversial incumbents.  The latter distinction is somewhat subjective, but it attempts to separate incumbents who were in real danger of losing from those who faced hopeless, underfunded challengers.  Endorsing a bunch of incumbents who would win anyways is an easy way for an endorser to increase the winning percentage.

Uncontroversial incuments:
WIN AZ-4 (2020) Paul Gosar
WIN MS-3 (2020) Michael Guest
WIN NY-27 (2020) Christopher Jacobs
WIN WV-Governor (2020) Jim Justice
WIN AZ-Senate (2020) Martha McSally
WIN MO-Governor (2020) Mike Parson
WIN NB-Senate (2020) Ben Sasse
WIN NJ-2 (2020) Jeff Van Drew
WIN CA-8 (2018) Paul Cook
WIN NY-11 (2018) Dan Donovan
WIN AZ-Governor (2018) Doug Ducey
WIN TN-8 (2018) David Kustoff
WIN TX-Ag Comissioner (2018) Sid Miller 

I didn't check for polls of the house races, since it is unlikely there were any for most of them.  There don't seem to have been any polls for the AZ-Senate, and there was only one in Nebraska.  For AZ-Governor, there was only one primary poll.  For WV-Governor, the polls don't seem to have changed significantly after Trump's endorsement of Justice.

For MO-Governor, Parson did better in the final result than in the two polls before Trump's endorsement, but those polls included a potential candidate (former governor Eric Greitens) who didn't end up running.  It is difficult to say whether Trump's endorsement had any effect.

Controversial incumbents:
WIN TX-12 (2020) Kay Granger
WIN UT-AG (2020) Sean Reyes
LOSS VA-5 (2020) Denver Riggleman
LOSS CO-3 (2020) Scott Tipton
WIN SC-Governor (2018) Henry McMaster
WIN AL-2 (2018) Martha Roby
LOSS AL-Senate (2017) Luther Strange

There don't appear to have been any public polls for TX-12, UT-AG, VA-5, CO-3, or AL-2.  The VA-5 loss was at a convention.

For SC-Governor, a poll shortly before Trump's endorsement of Henry McMaster had him at 33% and 50% undecided.  About two months later, a poll had him at 51%.  McMaster eventually won the runoff by 7%.

In AL-2, Martha Roby got 39% in the primary, but after Trump's endorsement got 68% in the runoff.  Trump may have helped get voters who supported the other candidates to back Roby.

In AL-Senate, a poll two weeks before Trump's endorsement of Strange had Roy Moore leading by 2%.  The first poll after Trump's endorsement had Moore leading by 19%, and he maintained a roughly 10% average lead for the rest of the race,  and won by that amount.  Trump's endorsement didn't help here.

Challenges Against Incumbents:
WIN KS-Governor (2018) Kris Kobach
WIN SC-1 (2018) Katie Arrington

For KS-Governor, polls were about even between Kobach and Jeff Colyer.  The final poll showed Colyer leading by 2%.  After Trump's endorsement, Kobach won by 0.1%.  Trump's endorsement doesn't seem to have had much impact here.

In SC-1, a poll a month before the election had Mark Sanford leading by 1%.  Trump's endorsement came the day of the primary.  Sanford eventually lost by 4%.  If Trump's endorsement had any effect, it was small.

OPEN SEAT PRIMARIES

WIN OH-15 (2021) Mike Carey
LOSS NC-11 (2020) Lynda Bennett
WIN MN-7 (2020) Michelle Fischbach
WIN TX-23 (2020) Tony Gonzales
WIN TN-Senate (2020) Bill Hagerty
WIN TX-7 (2020) Wesley Hunt
WIN TX-13 (2020) Ronny Jackson
WIN NH-Senate (2020) Corky Messner
WIN NH-1 (2020) Matt Mowers
WIN TX-11 (2020) August Pfluger
WIN MT-AL (2020) Matt Rosendale
WIN PA-7 (2020) Lisa Scheller
WIN AL-Senate (2020) Tommy Tuberville
WIN CA-Governor (2018) John Cox
WIN FL-Governor (2018) Ron DeSantis
LOSS WY-Governor (2018) Foster Friess
WIN MI-Senate (2018) John James
WIN GA-Governor (2018) Brian Kemp
WIN UT-Senate (2018) Mitt Romney

There don't appear to have been any public polls for  NC-11, MN-7, TX-7, or PA-7.

In OH-15, a poll after Trump's endorsement of Carey found him leading with 20%, and he won with 36%.  It is reasonable to think that Trump's endorsement provided a big boost, but this can't be proved with polling data.

In TX-23, Tony Gonzales led the primary by 5% before Trump's endorsement, and won the runoff by 0.2%, so Trump's endorsement doesn't seem to have helped here.

In TN-Senate, Trump endorsed Bill Hagerty before he was even in the race.  This froze out some elected officials (like Rep. Mark Green) who were considering running.  Hagerty led from the beginning, and won the primary comfortably.  Trump's endorsement made a huge difference here.

In TX-13, Ronny Jackson got only 20% in the primary, shortly after Trump's endorsement, but grew to 56% in the runoff.  Perhaps Trump's endorsement helped over time.

In NH-Senate, Corky Messner gained steadily after Trump's endorsement and won comfortably.  The endorsement may have helped here.

In NH-1, Matt Mowers gained in the polls and won easily, so Trump's endorsement may have helped here.

In TX-11, there doesn't seems to have been any polling, but since August Pfluger won easily, it is reasonable to think Trump's endorsement helped signigicantly.

In MT-AL, there isn't enough evidence that the results changed after Trump's endorsement.

In AL-Senate, polling shifted substantially toward Tommy Tuberville after Trump's endorsement.  Notably, Trump campaigned agressively against Jeff Sessions, unlike many other endorsements that were just positive tweets.

For CA-Governor, John Cox gained at most a couple points after Trump's endorsement in the jungle primary, so the endorsement didn't seem to help much here.

For MI-Senate, polling swung to John James after Trump's endorsement.  Trump's endorsement seems to have helped here.

For FL-Governor, Adam Putnam led most early polls, but after Trump's endorsement, Ron DeSantis took the lead, and eventually won comfortably.  Trump's endorsement certainly helped here.

For WY-Governor, Trump endorsed Foster Friess on the day of the primary, too late to have any impact on the race.

For GA-Governor, Brian Kemp had already taken a significant lead by the time Trump endorsed him.  He won by a larger margin, so Trump's endorsement may have helped to run up the score.

For UT-Senate, all polls occurred after Trump's endorsement.  Mitt Romney was always a strong favorite here, so it likely didn't make much difference.

Trump's endorsements in open seat races were still somewhat cautious.  Fischbach, Hunt, Rosendale, Scheller, Cox, Kemp, and Romney were all clear favorites before Trump endorsed them.  Romney (and Ben Sasse) faced more pro-Trump challengers, and eventually voted for impeachment.  Many of Trump's other endorsements were candidates who were co-leaders (DeSantis, James) or in fields of unknowns.

INFORMED VOTER POLLING

Another way of evaluating the impact of Trump endorsements is polls that ask voters about a race before and after informing them about his endorsement.  One example is a poll of the GA governor primary by InsiderAdvantage.

GA-Governor (Trump endorsed David Purdue)
Before: Kemp 41, Purdue 21, Jones 11
After: Kemp 34, Purdue 34, Jones 10
Purdue increases by 13, and Kemp drops by 7.

Similar polls have been conducted by Club for Growth, which endorsed each of the candidates that Trump endorsed.

AL-Senate (Trump endorsed Mo Brooks)
Before: Brooks 55 Britt 12, Und 23
After: Brooks 72 Britt 13, Und 9
Brooks gained 17, mostly from undecideds.

NC-Senate (Trump endorsed Ted Budd)
Before: Budd 21, McCrory 45, Walker 13, Und 21
After: Budd 52, McCrory 28, Walker 8, Und 12
Budd gains 31, pulling from all the other options.

OH-16 (old)/OH-13 (new) (Trump endorsed Max Miller)
Before: Miller 39, Gonzalez 30, Und 31
After: Miller 69, Gonzalez 17, Und 14
Anthony Gonzalez later decided not to run for reelection.

Note that these shifts are the best case scenario, since not all voters will hear about Trump's endorsement, and these polls only provide this one additional piece of information for voters to consider.

CONCLUSION

Donald Trump's endorsements had essentially no impact on primary races with incumbents.  In AL-Senate, the polls actually moved against the candidate he endorsed.  There were two cases where Trump-endorsed challengers beat incumbents.  However, Jeff Colyer had not been elected governor in his own right, and Kris Kobach was likely the favorite from the beginning.  In SC-1, Mark Sanford only won the 2016 primary 56-44, so he had serious baggage prior to Trump's late endorsement.

Trump's endorsements had a more significant impact on open seat races.  Bill Hagerty, Tommy Tuberville, August Pfluger, Mike Carey probably owe their victories to Trump.  In other races, Trump seems to have helped less, and in some, he may not have helped at all.

The informed voter polls show that voters are more likely to support a candidate endorsed by Donald Trump--up to 30% of voters switched, in some cases.  However, in a real campaign, voters base their votes on a combination of factors, which explains why such dramatic shifts have not been observed in actual campaigns.

Trump's endorsements remained somewhat cautious approach prior to 2021.  Since losing the 2020 election, Trump has pursued a different strategy.  He has made many more endorsements, including downballot races like state legislatures.  He has also shown far less concern for electability, endorsing some candidates who seem to be clear underdogs in either primaries or generals.  This will provide a clear test of his continuing influence on Republican primary elections.

Michigan Redistricting: State Senate Map Approved

Michigan's Independent Redistricting Commission has passed a state senate district map.

Interactive versions of the map are available at Dave's Redistricting and MICRC.

Michigan State Senate Map-Dave's Redistricting
Michigan State Senate Map-MICRC

Here are brief district descriptions.  The partisan statistics come from Dave's Redistricting; they are averages of several statewide races.

1. 29R, 71D SC Detroit, Taylor

2. 26R, 74D Dearborn, Dearborn Heights

3. 26R, 74D central Detroit, Warren, Madison Heights

4. 48R, 52D S Wayne

5. 41R, 59D Canton, Westland

6. 31R, 69D Livonia, Redford, Farmington Hills

7. 26R, 74D Southfield, Pontiac, Bloomfield Hills

8. 22R, 78D N Detroit, Royal Oak

9. 51R, 49D Troy, Rochester Hills, Sterling Heights

10. 34R, 66D E Detroit, Warren, Sterling Heights

11. 50R, 50D Macomb Twp, Clinton Twp, Roseville

12. 53R, 47D Lake St. Clair shoreline

13. 44R, 56D West Bloomfield, Novi, Northville, Plymouth

14. 45R, 55D N Washtenaw, Jackson

15. 27R, 73D S Washtenaw

16. 63R, 37D Monroe, Lenawee, Hillsdale

17. 65R, 35D S Berrien, Cass, St. Joseph, Branch, E Calhoun

18. 62R, 38D W Calhoun, Barry, SE Kent, E Allegan

19. 42R, 58D Kalamazoo, Antwerp Twp

20. 59R, 41D N Berrien, Van Buren, W Allegan, SW Kent

21. 43R, 57D W Ingham, Eaton

22. 63R, 37D Livingston, S. Genessee

23. 59R, 41D W Oakland

24. 66R, 34D N Oakland, NW Macomb

25. 68R, 32D St. Clair, Sanilac, Huron

26. 62R, 38D Lapeer, NE Genessee, S Saginaw, W Tuscola

27. 38R, 62D central Genessee

28. 45R, 55D East Lansing, Clinton, Schiawassee

29. 38R, 62D S Grand Rapids, Wyoming, Kentwood

30. 51R, 49D N Grand Rapids, central Kent, NE Ottawa

31. 62R, 38D Ottawa, Holland area

32. 53R, 47D Muskegon, Lake Michigan coast

33. 68R, 32D N Kent, Ionia, Montcalm, Newaygo, Lake

34. 64R, 36D central Lower Peninsula

35. 49R, 51D Saginaw, Bay, Midland

36. 68R, 32D NE Lower Peninsula

37. 58R, 42D NW Lower Peninsula

38. 59R, 41D Upper Peninsula

The existing map has five black-majority districts, while this map has zero.  There are five districts over 40% black (3, 6, 7, 8, 10), with district 7 topping out at 47% black.  Detroit is sliced into eight districts, up from five in the current map.  All 12 metro-Detroit area D state senators can run for reelection, so there will be quite a scramble for seats, and a couple will probably be left out.  There are also plenty of state reps. who will want to move up, creating more contentious primaries.

1. (Safe D) Stephanie Chang will likely run here.  Erika Geiss also lives here, but could move to new 4.

2. (Safe D) This seat now has a significant Middle Eastern population.  Sylvia Santana represents most of this seat and will probably run here.

3. (Safe D) At least one of Adam Hollier and Marshall Bullock will probably run here, though one could run in either 8 or 10.

4. (Lean D) This area has moved toward Trump, but votes more D downballot.  Erika Geiss represents much of this seat, but lives in Taylor (in district 1).  Geiss is black and quite liberal, and may not fit well in this working class seat.  Former rep. Pat Somerville (R) would be a good candidate, if he were interested.

5. (Safe D) I'm not sure where in Livonia Dayna Polehanki lives, but this seat is likely hers if she wants it.  Otherwise, she could run in district 6.

6. (Safe D) Betty Jean Alexander is a political lightweight who beat a white incumbent in a huge primary upset in 2018.  She will likely run here, but could face Livonia incumbent Dayna Polehanki.

7. (Safe D) The most black district on the map is mostly in Oakland.  It will likely see a primary between white incumbents Jeremy Moss and Rosemary Bayer.

8. (Safe D) Mallory McMorrow lives here, and will probably run here, though the majority of her current district is in new 9.  She could face a primary from a Detroit candidate.

9. (Lean R) State rep. Michael Webber (R) may run here.  Mallory McMorrow (D) represents about 2/3 of this seat, but lives in new 8.

10. (Safe D) Paul Wojno will likely run here.  He could face a primary from a Detroit candidate.

11. (Tossup) This slice of Macomb has moved R, but votes more D downballot.  Michael MacDonald (R) lives here.

12. (Lean R) This distict hugging the Lake St. Clair shoreline is actually a good draw for Rs.  Unlike the congressional and state house maps, the Grosse Pointes are not drowned in a Detroit district.  State rep. Pam Hornberger (R) narrowly lost a state senate special primary in 2021, and is the likely R candidate here.

13. (Lean D) Ten years ago, this would have been an R district, but these upscale suburban areas moved left under Trump.  This district borders on safe D, and only the hope of a suburban backlash is keeping it competitive.  No incumbent lives here.

14. (Lean D) In one of the outrageous pro-D gerrymanders on the map, Ann Arbor is split in half in an attempt to drown most of Jackson County in a D district.  Possible student turnout dropoff and the possibility of an Ann Arbor progressive being nominated are only barely keeping this seat competitive.  State rep. Julie Alexander (R) could run here.

15. (Safe D) The rest of Washtenaw is safe for any D.  I don't know if Jeff Irwin lives here or in 14.

16. (Safe R) This seat is open, with old 17 incumbent Dale Zorn termed out.  State reps Bronna Kahle and TC Clements are running for this seat.

17. (Safe R) This absurd district takes a swath of rural territory from Berrien to Jackson counties.  No incumbent lives here, but Kim LaSata represents about 2/3 of this seat and could move.

18. (Safe R) This succeeds old 19, and goes from three whole counties to one whole county and parts of five others.  John Bizon shouldn't have any trouble here.

19. (Safe D) Mostly the same as old 20, plus or minus a couple townships.  Sean McCann was the first D to win this seat in 2018, but probably won't have much trouble this time.

20. (Safe R) This is a messier successor to old 26, stretching from Benton Harbor to the Grand Rapids suburbs.  Aric Nesbitt, who is the presumptive next R senate leader, lives in 19.  However, he will certainly run here, where the large majority of his constituents live.  Kim LaSata lives here, but could move to 17 to avoid a primary.

21. (Safe D) In another outrageous pro-D gerrymander, Lansing is split, and East Lansing is put a into separate district.  This district takes away the Eaton County base of Tom Barrett (R), who is running for Congress instead.

22. (Safe R) Livingston County will no longer share a district with Washtenaw, to the delight of folks on both sides of the county line.  Conservative Lana Theis faces a primary from a challenger unhappy with her refusal to endorse election fraud conspiracy theories.

23. (Safe R) Jim Runestad gets a significantly safer district, but could face a primary with Ruth Johnson if she chooses to move here.

24. (Safe R) This packs much of the most R territory in Oakland and Macomb.  Doug Wozniak just won a special election for a Macomb-based seat.  Ruth Johnson also lives here; while she doesn't represent much of this district now, she is well-known from her previous offices.  State rep. John Reilly could run if Johnson doesn't.

25. (Safe R) Dan Lauwers keeps almost all his existing district, and shouldn't have any trouble.

26. (Safe R) Kevin Daley is the only incumbent here, but could face a primary from a Saginaw or Genessee-based candidate.

27. (Safe D) This is a reasonable seat containing most of the core of Genessee County.  It is open, since D leader Jim Ananich is termed out.

28. (Lean D) This is the other half of the gerrymander that split East Lansing from Lansing.  There is a chance that this could be competitive due to turnout dropoff amongst MSU students and the chance of a D nominee too far left for the district.  State rep. Ben Frederick (R) would be a good candidate if he is interested.

29. (Safe D) This district was held by an R until 2018, but Grand Rapids has zoomed left under Trump.  Winnie Brinks will presumably run here.

30. (Lean R) Another gerrymander is splitting Grand Rapids between 29 and 30 to create a competitive district here.  Fortunately, the rural areas of Kent and Ottawa are still solidly R downballot, through the presidential numbers got much worse under Trump.  Mark Huizenga was elected in a special election in 2021, and should be a good candidate to hold this seat.

31. (Safe R) Roger Victory should have another easy victory here.

32. (Lean R) This seat loses heavily R Newaygo County and adds more competitive areas along the lakeshore in a mild pro-D gerrymander.  However, these areas have been moving right, so this district will still likely elect an R.  Curt VanderWall lives here, but has most of his territory elsewhere, while Jon Bumstead represents the majority of this seat, but lives outside it in Newaygo County.  Presumably, one of them will run here, and one will run elsewhere.

33. (Safe R) Rick Outman lives here, but the majority of his current constituents are in 34.  Jon Bumstead also lives here, but could move to 33.

34. (Safe R) This district has no incumbent, but Rick Outman could move here, since he represents the majority of it now.

35. (Tossup) This is another pro-D gerrymander, combining three mid-Michigan seats to make about the best district possible for Ds.  While all cities, Saginaw (blacks), Bay City (white working class), and Midland (upscale Rs) have little in common demographically.  A decade ago, this would have been safe D, but Bay County has moved right. Turnout in Saginaw and candidate quality have long been a problem for Ds.  With Jim Stamas term-limited, there is no incumbent here.  State rep. Annette Glenn is running.

36. (Safe R) This seat has no incumbent, but Curt VanderWall could move here.  State rep. Michele Hoitenga has announced a campaign for this seat.

37. (Safe R) This seat only slightly shifts from its current version.  With Wayne Schmidt term-limited, the seat is open.

38. (Safe R) This seat adds more area, and now has almost all of the Upper Peninsula.  Incumbent Ed McBroom has angered Trump due to his refusal to endorse election fraud conspiracy theories, but has yet to attract a primary challenger.

Summary of Ratings:

Safe D: 13 (1, 2, 3, 5, 6, 7, 8, 10, 15, 19, 21, 27, 29)

Lean D: 4 (4, 13, 14, 28)

Tossup: 2 (11, 35)

Lean R: 4 (9, 12, 30, 32)

Safe R: 15 (16, 17, 18, 20, 22, 23, 24, 25, 26, 31, 33, 34, 36, 37, 38)

The map is clearly gerrymandered to help Ds in the name of "partisan fairness".  Grand Rapids, Lansing, and Ann Arbor are split for no legitimate community of interest reason.  District 35 is also drawn to maximize the chance of electing a D.  The only noticably good draw for Rs is district 12.  The lack of any majority black districts is likely a violation of the Voting Rights Act.  Districts 1, 3, 6, 8, and 10 split Detroit, and have no good community of interest justification.  Districts 17, 18, 20, and 26 are also poor communities of interest.  The map looks sloppy, and breaks 29 counties (85 total breaks), up from 6 counties (7 total breaks) on the existing map.  This poor map indicates a need for major reform of the redistricting process in Michigan.

Coverage of last decade's redistricting:

2011-2012 Michigan Redistricting