Taking a stand against Donald Trump is guaranteed to bring Republicans online abuse, primary election challengers and barbs from the former US president himself. But it is also proving lucrative as donors scramble to breathe life into the anti-Trump resistance.

Liz Cheney, a Republican congresswoman from Wyoming and leading Trump critic, enjoyed her second consecutive record fundraising quarter with $1.88m from April to June, according to financial reports filed with the Federal Election Commission. She had raised $1.54m in the first three months of the year.

Adam Kinzinger, an Illinois congressman who defied party leaders by joining Cheney on the House of Representatives select committee investigating the 6 January insurrection, raised almost $2m in the second quarter, while his political action committee (Pac) took in $1.5m-plus.

And Americans Keeping Country First, which describes itself as the “only Super Pac dedicated solely to defending the members of Congress who took votes of conscience to impeach or convict President Trump” after the US Capitol riot, reported $525,000 in income through the end of June.

The hefty fundraising numbers suggest that, while Trump retains an iron grip on the Republican party, there is still significant money behind efforts to wrest it free from the man who was twice impeached and lost the House, Senate and White House.

“That is a bright sign for the Republican dissidents to be able to raise that kind of money,” said Charlie Sykes, a journalist and author of How the Right Lost Its Mind. “It’s unfortunate that it doesn’t change the dynamic that the Republican base is what it is.

“But it’s a reminder that there is a constituency for Republicans who are willing to break with Trump. It’s a signal that other Republicans can see that if in fact they do the right thing, they are not going to be completely abandoned, that there is potentially some support there.”

Breaking from Trump carries a political price. Cheney – daughter of former vice-president Dick Cheney – has already been censured by the Wyoming Republican party and ousted as the House Republican conference chair.

She, Kinzinger and other Republicans who voted to impeach Trump are set to face primary challenges from candidates endorsed by the former president ahead of next year’s midterm elections.

But the healthy cashflow suggests that the mavericks will not go down without a fight. Cheney out-raised her most prominent opponent, Wyoming state senator Anthony Bouchard, who took in a more modest $550,000 up to the end of June. Kinzinger challenger Catalina Lauf raised a little more than $350,000.

Americans Keeping Country First’s haul “puts it on or above the fundraising pace of independent political groups going after the few remaining Republican Trump critics in Congress”, Axios reported.

The figures come after a rough week for Trump. Susan Wright, whom he endorsed,, lost to fellow Republican Jake Ellzey in a primary in Texas – albeit one where Democrats were able to cast protest votes – and Senate Republicans defied his urgings to reject a bipartisan infrastructure deal.

Sykes added: “There are some green shoots. Those elements are all indications of possible vulnerability. Losing that primary where he had gone all in is significant but it’s a long way to go. It’s going to be a drip, drip, drip. There will be a lot of opportunities for other Republicans to find off-ramps if they’re looking for it.”

Declaring an end to Trump’s dominance of the party, however, usually proves wishful thinking. He raised more than $100m in the first half of 2021, far more than any other Republican and a remarkable sum for a former president. Many senior party figures still promote his false claim of a stolen election – at least in public.

Tim Miller, writer-at-large for the Bulwark website and former political director of Republican Voters Against Trump, said: “There are plenty of Republican donors that didn’t support the insurrection but are just going along to get along with Donald Trump. These are not profiles in courage but I could see them wanting to assuage their guilt by rewarding Cheney and Kinzinger.

“There are people that maybe don’t want to speak out and earn the ire of Donald Trump but want to be supportive; I know people like that. I’m not surprised that with the combination, from your quiet anti-Trump Republicans to your ‘Never Trumpers’, to some good-natured Democrats, you can pull together money. The question is whether that translates into popular support.”

Electoral strategy may also play a part. Some Republicans, and their financial backers, apparently regard Trump as a toxic figure in many suburban districts crucial to midterm success. Some of his anointed candidates, such as Herschel Walker for senator in Georgia, might soar in a primary but flame out in a general election. Money is therefore flowing to some more moderate rivals.

Wendy Schiller, a political science professor at Brown University said: “Whatever the polls say, whatever the voting base is, who is actually fueling the Republicans in terms of campaign contributions? You’re seeing a distinct split. You’re seeing some portion of the party – and that encompasses corporations and the Chamber of Commerce, which really likes stability – keeping the anti-Trump faction in pretty good shape at least with Kinzinger and Cheney.

“If you’re the Republicans and you desperately need to keep the suburbs you won back in 2020, you have to do something about the Trump surge because suburban voters are not going back to Trump. So if you have a GOP person in 2020 who took back a competitive suburban seat in that election, that person is going to have a hard time keeping the seat if they are too closely aligned with Trump.

“That’s where the Cheney-Kinzinger wing of the party has got to be able to raise enough money to keep those suburban GOPers in contention in a primary against a Trump supported opponent… finding a way to keep those people in the game in the primary from January to August.”