SIOUX CENTER, Iowa — Stunning new revelations about former President Donald Trump’s fight to overturn the 2020 election have exposed growing political vulnerabilities as he eyes another presidential bid.

A former White House aide last week described Trump as an unhinged leader with no regard for the safety of elected officials in either party as he clung to power on Jan. 6, 2021. The testimony from the congressional panel investigating the U.S. Capitol attack provided a road map for prosecutors to potentially charge Trump with a crime, some legal experts say.

Republican voters — and Trump’s would-be rivals in the 2024 presidential race — took notice.

In Iowa, the state expected to host the first presidential nominating contest, several voters signaled that they were open to another presidential candidate even if Trump were to run again.

At the same time, some conservative media outlets issued scathing rebukes of the former president. Aides for multiple GOP presidential prospects also indicated, publicly and privately, that they felt increasingly emboldened to challenge Trump in 2024 following the explosive new testimony.

Nikki Haley, Trump’s ambassador to the United Nations, drew roughly 350 conservative activists last Thursday to a congressional fundraising barbecue in Sioux County, Iowa, where Trump won 82% of the vote in 2020.

There was ample evidence of Trump fatigue. Interviews with a dozen attendees revealed strong interest in a 2024 alternative, even if Trump is on the ballot.

“You’d be hard-pressed to find people in this area who support the idea that people aren’t looking for someone else,” said Dave Van Wyk, a transportation company owner. “To presume that conservative America is 100% behind Donald Trump is simply not the case.”

For some Republican voters, that was the feeling before the latest House hearing’s stunning new testimony.

Former White House staffer Cassidy Hutchinson on Tuesday offered previously unknown details about the extent of Trump’s rage in his final weeks of office, his awareness that some supporters had brought weapons to the city on Jan. 6 and his ambivalence as rioters later laid siege to the Capitol.

Upset at the size of the crowd at his “Stop the Steal” rally — many supporters avoided entering because they were armed and didn’t want to go through metal detectors — Trump said words to the effect of “I don’t care that they have weapons. They’re not here to hurt me,” according to Hutchinson. She recalled hearing about a separate incident after the rally in which Trump tried to grab at the steering wheel of the presidential vehicle to go to the Capitol to join his supporters.

That detail has caused pushback. The agent who was driving the vehicle and another official were reportedly prepared to testify under oath that Trump never lunged for the wheel.

But the renewed concern was evident.

The conservative Washington Examiner’s editorial board said Hutchinson’s testimony “ought to ring the death knell” for Trump’s political career. “Trump is unfit to be anywhere near power ever again.”

The often Trump-friendly New York Post blasted the headline: “Tyrant Trump.”

And the conservative editorial page of the Wall Street Journal wrote, “Just when it seems as if Donald Trump’s behavior after his 2020 loss couldn’t possibly look worse, a new piece of wild testimony arrives.”

Conservatives have shared serious concerns about Trump repeatedly in recent years. And in every case, the former president has emerged largely unscathed, sometimes stronger. He has been caught on video bragging about sexual assault; he instigated a violent attack on the Capitol; and he has been twice impeached.

Yet Trump is sitting on campaign funds that exceed $101 million and remains deeply popular with many Republican voters. And GOP candidates from Arizona to Pennsylvania to Georgia have been battling one another this midterm season for his support.

“President Trump is in a stronger position now than at anytime before,” Trump spokesperson Taylor Budowich said.

But even before last week’s revelations, a new poll from Associated Press-NORC Center for Public Affairs Research found that 48% of U.S. adults say Trump should be charged with a crime for his role in the Capitol attack.

Views on Trump’s criminal liability break down predictably along party lines, with 86% of Democrats and 10% of Republicans saying Trump should be charged. Still, the fact that nearly half the country believes he should be prosecuted is a remarkable position for the former president, pointing to the difficulties he could face if he makes another run at the White House.

Trump reported raising nearly $9 million in March and April combined. Figures for May and June were not yet available, but aides to the former president say his fundraising has remained strong.

Republicans are bracing for Trump to announce an unusually early bid for the White House, a move designed in part to shield him from a stream of revelations emerging from investigations into his attempts to cling to power after his election loss.

The timing of a formal announcement is uncertain. But Trump recently surprised some advisers by saying he might declare his candidacy on social media without warning even his own team, and aides are scrambling to build out basic campaign infrastructure in time for an announcement as early as this month.

Former New Jersey Gov. Chris Christie, eyeing a presidential bid in 2024, said he was hearing concerns about Trump from donors and voters alike before the most recent testimony.

“People are concerned that we could lose the election in ’24 and want to make sure that we don’t nominate someone who would be seriously flawed,” Christie said.

Maryland Gov. Larry Hogan, who is also considering a 2024 run, considers Trump beatable in a GOP primary even if Republican voters aren’t paying close attention to the congressional hearings.

“His approval among Republican primary voters has already been somewhat diminished,” Hogan said. “Trump was the least popular president in American history until Joe Biden.”

Aides for other Republican presidential prospects said privately last week that they believe Trump’s standing with Republican voters has been in steady decline.

The New York Times contributed.