(Bloomberg) -- Donald Trump could hurt Republicans’ chances of regaining control of Congress in the 2022 midterms, just by endorsing the candidates working so hard to win his backing.

The former president is studying races and plans to bestow his superlative-laden endorsements around the country in many 2022 primary or general election contests for the U.S. House, Senate and governorships, according to a person familiar with his thinking.

While those nods can still be the golden ticket in a Republican primary and solidly GOP districts, they also can energize independents and Democrats who don’t like Trump in competitive districts -- risking defeat for Republican candidates in the general election and with it possible control of the House, according to studies of the 2018 and 2020 campaigns.

History is on the Republicans’ side. Midterm elections generally favor the party out of power and redistricting is expected to change district lines in a way that gives the GOP an advantage.

Republican leaders in the House obeyed Trump’s wishes by ousting their No. 3 leader, Representative Liz Cheney of Wyoming, on Wednesday for repudiating his false claims of a stolen election. His anti-endorsement of Cheney means he is looking for a primary candidate to wreck her 2022 re-election bid.

”Almost everyone in the Republican Party, including 90% of Wyoming, looks forward to her ouster — and that includes me!” he said in a statement Wednesday.

Five incumbent Democrats are leaving the House, which the party holds by fewer than a half-dozen seats, and only one U.S. Senate seat needs to change hands for Minority Leader Mitch McConnell to be back in charge of the upper chamber.

South Carolina’s First Congressional District includes Charleston as well as coastal resort towns populated by the suburban moderates both parties are clamoring to win. In the 2018 Republican primary, Katie Arrington was neck and neck with the incumbent, former Governor Mark Sanford, before Trump endorsed her on the day of the primary.

Trump’s endorsement added about 2 percentage points and Arrington won the primary without a runoff, said Robert Cahaly, an Atlanta-based Republican pollster. But Arrington lost the general election to Democrat Joe Cunningham by about 4,000 votes, and Trump’s unpopularity with suburban voters was a factor.

In Colorado, Trump’s endorsement last year of Republican Senator Cory Gardner in a race that leaned Democratic helped shore up his standing among Republicans, according to David Flaherty, a Colorado-based Republican-leaning pollster and founder of Magellan Strategies. A Magellan poll in October showed Gardner had 89% support among Republicans.

But Flaherty said Trump’s backing alienated unaffiliated voters who turned out in large numbers in the general election, and Gardner lost to Democrat John Hickenlooper by more than 9 percentage points.

That dynamic means Trump could swing a close race the wrong way for Republicans in a suburban district by shifting blame for his actions and policies onto the GOP candidate.

“In some ways, Republicans in swing districts face a theoretical dilemma,” said GOP pollster Whit Ayers, whose clients have included senators and governors. “Would you rather lose by two points because a Trump endorsement generated a Democratic backlash, or would you rather lose by two points because the lack of a Trump endorsement depressed Republican turnout?”

The National Republican Congressional Committee has internal polling, partly shared with Republican Party officials in April, that showed Trump’s unfavorable ratings in core battleground districts were 15 points higher than his favorable ones, according to the Washington Post.

“The Republican Party cannot win swing districts where Donald Trump is still the dominating face and voice of this party,” Rahm Emanuel, President Barack Obama’s chief of staff, said Sunday on ABC’s “This Week.”

“And that’s where they’re going to take a historic opportunity in a midterm and pass it right by.”

Some 120 Trump-endorsed candidates won all but two Republican congressional primaries in 2020, according to a Ballotpedia accounting. But in general election races, 40 of his 183 endorsed candidates lost -- and almost all of them ran in competitive districts. That includes 27 of the 67 candidates he endorsed after a primary who lost.

There are 68 U.S. House races in 2022 initially targeted by the NRCC and the Democratic Congressional Campaign Committee that are considered competitive based on the Cook Political Report’s partisan voter index. Six U.S. Senate races are also rated as toss-ups or lean toward one party.

In 2018, the GOP could have won at least 11 more House seats and four Senate seats had Trump refrained from endorsing, according to a study by researchers at American University and Florida State University of 80 races in which Trump backed the Republican.

The researchers examined fund-raising of endorsed candidates and their opponents before and after Trump’s seal of approval. They found that the Democratic opponent shared in the boost, raising an average $2,390 more from 31 extra donors than the average congressional candidate per day after a presidential endorsement.

‘Careful What They Wish For’

The study also showed that a Trump endorsement decreased a candidate’s vote share, meaning those who received his support were less likely to win than those who did not.

“Based on the evidence from 2018, certain candidates hoping to catch the eye of the president in future elections and receive an endorsement may want to be careful what they wish for,” the researchers concluded.

The findings reinforce the concerns among some Republican donors and leaders that Trump’s vow to challenge disloyal GOP incumbents could create a sea of untested challengers who can’t win.

Brian Jack, who was Trump’s White House political director, disputed the research and the concerns. He said Trump led more than 50 tele-rallies for congressional candidates last fall -- and those candidates won every race that was rated a “toss-up,” “leans Republican” and “likely Republican.”

“The strength and success of President Trump’s endorsement record speaks for itself,” Jack said.

Trump senior adviser Jason Miller said the former president’s endorsement can clear a GOP primary field, get non-traditional Republican voters to turn out in general election races, and that he has “most powerful name in electoral politics right now.”

Mixed Record

The former president boasts that his endorsements brought 128 or 122 wins -- depending on when he’s asked -- and two defeats in GOP primaries in the last election cycle. That’s essentially true, according to a Ballotpedia accounting, though the victories include 18 unopposed candidates and 93 incumbents, who rarely lose a primary.

He’s already endorsed nine candidates for the 34 Senate seats up in 2022, and it’s the most tangible way he can influence politics now that he’s out of power. While his ability to trumpet those endorsements is muted by his inability to use social media, the endorsed candidates can certainly brand themselves as the Trump-approved choice.

Earlier this month, Trump announced his support for Susan Wright, who was running in a special election to replace her late husband, Representative Ron Wright, in a safe Republican district in Texas. He claimed that “Susan surged after I gave her an endorsement last week.”

Wright was the top vote-getter but failed to avoid a runoff. In fact, almost 70% of the votes cast for Republicans in the crowded field were for someone besides Wright.

The trend of Trump’s endorsement record appears poised to apply to the midterms next year. A survey of 2,022 individuals across 50 states in January for the Covid States Project found that while 45% of Republicans said Trump’s endorsement of a candidate would increase their support for that candidate a lot or somewhat, 72% of Democrats and 37% of independents said it would decrease their support.

“Certainly on balance, this would suggest that an endorsement from Trump could be hurtful in the general election with independents,” said David Lazer, a professor at Northeastern University and a project co-leader. “If you lose a couple points among independents in a close race, that could be the ballgame.”

So far, Trump has endorsed 22 candidates for Senate, House and statewide races, as well as for state Republican Party leadership and Representative Elise Stefanik to replace Cheney in the GOP House leadership.

Trump touts his endorsement as the key to winning any race.

“The fact that I give somebody an endorsement has meant the difference between a victory and a massive defeat,” Trump said on a March podcast with Fox News contributor Lisa Boothe. “They’re all going to win, and they’re going to win big,” he said.

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