Their angry reactions, in the 24 hours since Mitt Romney and John McCain urged millions of voters to cooperate in a grand strategy to undermine Trump's candidacy, has captured the seemingly inexorable force of a movement that still puzzles the Republican elite and now threatens to unravel the party they hold dear.
In interviews, even lifelong Republicans who cast a ballot for Romney four years ago rebelled against his message and plan.
"I personally am disgusted by it — I think it's disgraceful," said Lola Butler, 71, a retiree from Mandeville, Louisiana, who voted for Romney in 2012. "You're telling me who to vote for and who not to vote for? Please."
"There's nothing short of Trump shooting my daughter in the street and my grandchildren — there is nothing and nobody that's going to dissuade me from voting for Trump," Butler said.
A fellow Louisiana Republican, Mindy Nettles, 33, accused the party of "using Romney as a puppet" to protect themselves from Trump because its leaders cannot control him.
"He has a mind of his own," Nettles said. "He can think."
The furious campaign now underway to stop Trump and the equally forceful rebellion against it captured the essence of the party's breakdown over the past several weeks: Its most prestigious guardians, misunderstanding their own voters, antagonize them as they attempt to reason with them, driving them even more energetically to Trump's side.
As Romney amplified his pleas Friday, Trump snubbed a major meeting of Republican activists and leaders after rumblings that protesters were prepared to demonstrate against him there, in the latest sign of Trump's breakaway from the apparatus of the party whose nomination he is marching toward.
As polls showed Trump likely to capture the Louisiana primary on Saturday, the biggest prize among states holding contests this weekend, the party establishment in Washington seemed seized by anxiety and despair. At the Conservative Political Action Conference, a long-running gathering of traditional conservatives, attendees feared that they were witnessing an event that has not occurred in more than a century: the breaking apart of a major American political party.
They spoke ruefully of "fidelity" lost and "values" forgone. They conceded a strange new feeling of powerlessness in the face of Trump's ascendance. And they mourned for a 162-year-old party that is starting to seem unrecognizable to them.
Robert Walker, a former Pennsylvania congressman, lamented that the nomination of Trump, with his vulgar style and ideological flexibility, "would rebrand the party in ways that would take us a long time to recover from."
Rick Santorum, a former Republican presidential candidate, warned of the "Republican Party potentially being torn up," and Sen. Ben Sasse of Nebraska groused about what would "actually make American great again." (It was not Trump.)
Steve Forbes, the publisher and two-time Republican presidential candidate, summed up the mood at the event.
"Parties," he said, "don't usually commit suicide," suggesting the party was well on its way with Trump.
The problem, for figures like Forbes and Romney, is that Trump's supporters seem profoundly uninterested at the moment with the image, expectations or traditions of the Republican Party, according to interviews with more than three dozen voters, elected officials and operatives. They are, in many cases, hostile to it.
"I want to see Trump go up there and do damage to the Republican Party," said Jeff Walls, 53, of Flowood, Mississippi.
From the moment Romney delivered it in a speech Thursday from Salt Lake City, his entreaty to voters struck many in the party as high-minded and impractical: He all but begged them to vote for Trump's rivals, thereby denying Trump enough delegates to clinch the nomination and force a contested convention this summer. Voters have not taken kindly to it, describing the request as a patronizing directive from an elite figure who thoroughly misunderstands their feelings of alienation from the political system.
Conservative talk radio shows lit up Friday with incensed callers who said they were "livid," "mad" and "on the verge of tears" as they listened to Romney scoldingly describe what he called Trump's misogyny, vulgarity and dishonesty, and urged them to abandon him.
"The Trumpists out there," predicted Rush Limbaugh, "are going to feel like the establishment is trying to manipulate them, sucker them — and they're just going to dig in deeper."
They did.
Kathy, a caller from Sun City, Arizona, told Limbaugh she was "absolutely livid by the Romney speech. He's condescending," she said, adding that he sounded like a "Democrat the whole time." Steve from Temecula, California, said he had a message for Romney: "The Republican electorate is not a bunch of completely ignorant fools."
"We know who Donald Trump is," he added, "and we're going to use Donald Trump to either take over the GOP or blow it up."
As Romney hopped between television stations Friday, proclaiming his dismay over Trump's crudeness, challenging his decency and questioning his integrity, he declared that his overtures were breaking through — though not necessarily to the audience he intended. In an interview conducted inside the headquarters of Bloomberg News in New York, far from the crucial primary voting states that could decide Trump's fate, he observed that office workers had offered their gratitude as he rode up to the studio.
"Just coming up the escalator," Romney said, people said, "'Thanks for what you did yesterday.'"
But outside that orbit, the response was less welcoming.
Trump's supporters and those backing his rivals, in interviews across the country, suggested that Romney's move was presumptuous and described him as out of touch and ineffectual. "They want to control the election because they don't like Trump," said Joann Hirschmann of Shelby Township, Michigan, a supporter of Gov. John Kasich of Ohio. "And I can understand that. But you have to let the people speak."
Frustrated Republicans seized on Romney's status as a party insider who was insulated from the realities, indignities and rage of average Americans headed to the polls this year. "He's an establishment figure," said Faith Sheptoski-Forbush of Romulus, Michigan. "So that's what you get."
She called Romney's diatribe against Trump "a desperate attempt" that left her deeply disappointed in him.
"What we need is the voice of the people," said Sheptoski-Forbush. "The voice of the people want Trump."