FT. WASHINGTON, Md. – Republican presidential front-runner Donald Trump cancelled, last-minute, his scheduled appearance here at the American Conservative Union’s annual conference, CPAC. Liz Mair, the spokeswoman for an anti-Trump effort who had planned to protest at his speech, is taking credit for keeping him at bay.

The New York businessman doesn’t have as much support here among conservatives as he seems to have among the general population of Republicans. Mair, who says she had commitments from about 50 people to join her protest, explained just how strong her disapproval is: She said in an interview Saturday she’d never vote for him — not even if he won the Republican nomination and faced off against Democratic front-runner Hillary Clinton.

“There are a lot of average Americans out there on the right who are terrified of this guy being president,” she said, adding she believed those voters would turn to a third-party candidate, a write-in or would simply stay home on election day rather than vote for Trump.

The idea turns on its head a fear members of the Republican establishment began to express as soon as Trump announced his White House bid last summer. Worried he’d launch a third-party run if he didn’t get the Republican nomination, party leaders got Trump to sign a loyalty pledge saying he wouldn’t run as an independent. They, in turn, pledged to support him as the nominee. The agreement seemed to head off the possibility that a third candidate would take votes away from the Republican ticket and hand the presidency to Clinton.

Trump is succeeding as a Republican, but the third-party threat from the right remains. It’s just less likely that third candidate will be The Donald. Instead, it could be the Libertarian former governor of New Mexico Gary Johnson or a yet-undetermined write-in.

Mair pointed to the success of Alaska Senator Lisa Murkowski, who beat the Republican nominee for her Senate seat in 2010 as a write-in on the ballot.

“It’s a lot harder to spell ‘Murkowski’ than it is to spell ‘Ryan’ or ‘Romney’ or ‘Walker’ or ‘Perry,’” she said, referring to her other ideas for Republican write-ins, House Speaker Paul Ryan, former Massachusetts Governor Mitt Romney, Wisconsin Governor Scott Walker and former Texas Governor Rick Perry. Romney, Walker and Perry have all run for president. Ryan was Romney’s running mate on the 2012 Republican presidential ticket.

Not everyone at CPAC intends to vote for a third party if Trump is the nominee. Several people asked by a reporter about the idea chuckled and walked away at the suggestion, refusing to give their names.

But Josh Paladino, a 19-year-old student at Hillsdale College in Hillsdale, Michigan, brought up the idea without any prompting. He said he so strongly disapproved of Trump that he was hoping Republican leaders would use whatever obscure party rules they could find to keep the nomination away from him. But if they couldn’t, he said, he’d vote for someone else.

“Hopefully a conservative can get on the ballot,” he said.