WASHINGTON — Republicans are feeling more bullish by the day about their chances in next year’s midterm elections as their voter enthusiasm rises, President Joe Biden’s approval rating slips and Democrats struggle to pass their policy agenda.

But one often unpredictable factor still looms large: former President Donald Trump.

Trump has ramped up his 2022 campaign activity in recent weeks, endorsing GOP candidates up and down the ballot, holding rallies across the country and raising money for his political groups. All the while, he has continued to spread his false claims about fraud in the last election and attack fellow Republicans he perceives as disloyal.

As the most popular and influential figure within the GOP, some party operatives fear Trump’s incessant focus on the past could complicate what is otherwise shaping up to be a favorable political environment — and ultimately be the biggest hindrance to their efforts to take control of the House and Senate.

“This should be a really good election year for Republicans. But the one question, the one unknown is, how is the former president going to approach it?” said Eric Tanenblatt, a longtime Republican operative and fundraiser based in Georgia. “Is he going to unify and encourage turnout from across the party, or is he going to try to suppress the vote for certain candidates?”

Trump has so far issued 41 endorsements to Republicans running in statewide and local races in 2022, an unusual level of activity from a former president, as he seeks to maintain his grip on the party.

Of those 41 candidates, eight are mounting primary challenges to a sitting Republican officeholder while 17 are running in open GOP primaries. Many of them have expressed support for the “audits” of the certified 2020 election results that Trump has sought.

Trump has also resumed holding political rallies, addressing crowds in Ohio, Florida, Arizona, Alabama and Georgia since the beginning of the summer. While the former president has increased criticism of Biden recently, particularly over the chaotic withdrawal of U.S. troops from Afghanistan and the migrant influx at the border, his focus at the rallies has primarily been on other Republicans and the last election.

At a rally in Georgia late last month, Trump escalated his attacks on Republican Gov. Brian Kemp for refusing to assist with his attempts to overturn the 2020 election results in that state. At one point Trump even suggested that one of Kemp’s possible Democratic opponents in 2022, Stacey Abrams, would be a better alternative.

Trump is scheduled to hold his next rally on Saturday in Iowa, which will host several key 2022 races and kick off the 2024 presidential nominating process. But some Republicans are concerned his involvement will backfire as the midterm elections draw closer, with the potential to energize the progressive and swing voters who turned out in droves to oppose him last year.

“For the most part, Joe Biden and the Democrats would welcome Trump doing a tour across America to make the election a referendum about Trump,” said veteran Republican strategist Mike DuHaime. “Most Republicans would privately hope Trump would stay away.”

Recent polls suggest Trump has maintained a firm grip on the GOP base since leaving office nearly nine months ago. A new Pew Research Center survey found that two-thirds of Republicans nationwide think Trump should remain a major national political figure and that 44% want him to run for president again.

The latest national Politico/Morning Consult poll showed that 81% of Republicans hold a favorable view of Trump. But that figure drops to 42% among independents and 8% among Democrats.

That dynamic presents a tricky balancing act for the GOP. Republican strategists say that while most of their candidates would welcome an endorsement from Trump in a primary, it could quickly become a liability in a general election, especially in battleground states and districts.

“Trump by himself is great for a Republican primary,” said Chuck Coughlin, an Arizona-based Republican consultant. “Trump by himself is not good for a general election.”

Republicans gain ground

Outside of Trump, Republicans say that several key political indicators are increasingly pointing in their direction. Biden’s job approval rating has fallen to a 44% average as he has dealt with the fallout from the Afghanistan evacuation, a resurgence of COVID-19 and some contentious negotiations with Democratic lawmakers over the size and scope of his economic agenda.

A Politico/Morning Consult survey last month showed that 58% of Republicans said they were “extremely” or “very” enthusiastic to vote in 2022, up 10 points from the summer. Republicans are also gaining ground in polls that ask voters which party they prefer to control Congress.

Midterm elections are historically favorable for the party that is out of power in a president’s first term, and Democrats are defending narrow majorities in the House and Senate.

GOP operatives acknowledge there is plenty of time for the political climate to shift over the next 13 months, especially as Trump steps further into the spotlight.

“Part of the challenge he’s going to have is, given his performance with independents, how does he help the standing of Republicans?” said longtime Republican pollster David Winston.

Republican operatives say Trump will need to be selective about where he campaigns to have a positive impact on the party’s chances in the midterms. For instance, Trump is much more popular in red-leaning states like Iowa, which he carried twice, than he is nationally. Ahead of his rally this weekend, a Des Moines Register poll found that 53% of Iowa voters view him favorably, his highest mark ever in the survey.

“In a place like Iowa, he’s a net positive. In a place like the Atlanta suburbs, he’s probably not a net positive there,” said Scott Jennings, a veteran Republican strategist. “It depends heavily on the territory.”

Even for those Republicans who are receptive to Trump’s 2020 election claims, they hope he begins to focus more on securing victories in the midterms.

Steve Scheffler, a Republican National Committee member from Iowa and the president of the Faith and Freedom Coalition, said he shares Trump’s view that there was fraud in the last election and that states should enact more restrictive voting laws as a result.

But now it’s time to turn attention to the next election, he said.

“We’re a lot better off as a party to focus on things we can do things about,” Scheffler said. “What we can do things about is getting our people elected in 2022.”