A wave of prominent Republicans have announced their intention to skip the party's national convention in Cleveland this summer, the latest sign that Donald Trump, who last week secured the delegates needed to clinch the Republican presidential nomination, continues to struggle in his effort to unite the party behind his candidacy.
The list of those who have sent regrets includes governors and U.S. senators — almost all facing tough re-election fights this year — and lifelong party devotees who have attended every convention for decades. Some are renouncing their seats like conscientious objectors.
"I could not in good conscience attend a coronation and celebration of Donald Trump," wrote one Indiana delegate, Josh Claybourn, in a blog post resigning his position.
The coolness toward Trump amounts to a remarkable rebuke. A broad range of party leaders are openly rejecting the man who might be their nominee. And the July 18-21 convention, usually a moment of public catharsis for political parties after contentious primaries, is shaping up to be another reminder of the disarray and disunity that is still rocking the Republican Party after a bitter 17-way fight for the nomination.
Even the two highest-ranking Republicans in the convention's host state of Ohio — Gov. John Kasich and Sen. Rob Portman, who is fighting to hold onto his seat — do not know if they will set foot in the convention hall.
Kasich, who only four weeks ago quit the presidential campaign himself and has not endorsed Trump, has no idea "what role if any he will have," a spokesman said. He will be in Cleveland that week but has no plans, as of now, to partake in any official convention activities.
Several other of Trump's former rivals for the nomination have either said they will not attend or have not yet committed. Jeb Bush, the former governor of Florida, will not be there. Neither will Sen. Lindsey Graham of South Carolina.
"I'm sure it will be fun; I'm sure it will be entertaining," Graham said last week. "And I can watch it on TV."
Sen. Rand Paul of Kentucky, who is a delegate as well as a former presidential candidate, has yet to decide. "TBD," a spokesman said. "The schedule is still being firmed up."
At least two former competitors of Trump's are expected to attend: Gov. Chris Christie of New Jersey and Sen. Marco Rubio of Florida, who last week offered his services as a speaker should they be wanted.
Among those staying away include some major corporations like Coca-Cola, Microsoft and Hewlett-Packard.
And some who do plan to be there might find the atmosphere somewhat uncomfortable.
Trump still has not fully reconciled with Speaker Paul D. Ryan, the convention's chairman who said in early May that he was not ready to support the nominee and would relinquish the role if asked.
Trump is also at odds with the head of the Republican Governors Association, Susana Martinez of New Mexico, who will lead her state's delegation in Cleveland. Martinez also has withheld her endorsement, a slight that evidently prompted Trump to attack her performance as governor last week.
Scheduling conflicts seem to be a surprisingly common excuse for missing an event that was announced a year and a half ago. Others offered mushy noncommitments.
"Just as they're firming up the schedule, it kind of looks like there's a lot of stuff for me to do," said Sen. Ron Johnson of Wisconsin, explaining why he probably couldn't make it.
Asked if Trump had anything to do with his reluctance, Johnson, who is in a heated re-election campaign, broke into a big smile and said, "Oh, of course not."
Gov. Rick Snyder of Michigan, a state Trump has said he believes the Republicans can wrest from Democrats this year, also might have more important things to do at home.
"Michigan has some pressing challenges right now," a spokeswoman said last week, "and state issues are his foremost priority."
Snyder is one of at least nine Republican governors who are either noncommittal or skipping the convention: Kasich, Brian Sandoval of Nevada, Charlie Baker of Massachusetts, Bruce Rauner of Illinois, Larry Hogan of Maryland, Nikki R. Haley of South Carolina, Matt Mead of Wyoming and Nathan Deal of Georgia.
"I don't even want to be involved," Hogan said in an interview in March. "It's a mess. I hate the whole thing."
Just about every Republican senator in a difficult race is staying away, fearful of what the association with Trump might do to reputations back home. Sen. John McCain of Arizona will join four of the five living former Republican nominees in skipping the convention.
"I'm in a very tough re-election campaign," he said last week, explaining his expected absence.
Sens. Kelly Ayotte of New Hampshire and Mark S. Kirk of Illinois, two of the most endangered Republican incumbents, also will be nowhere near Cleveland that week.
Portman, another senator in a tight race, said his time would be better spent holding a mini-convention of his own in Cleveland, which he plans to do with events for veterans, the homeless and his volunteers.
"I've spoken at every convention since 1996," he said. "Nobody listens; nobody covers it."
This mass avoidance might seem, on its surface, to be yet another example of the party elite snubbing Trump in the kind of rejection that he would welcome as a professed political outsider. But it also reflects a deeper and more dangerous problem for him: Trump's popularity with Republicans remains uncomfortably low.
The candidate's own party generally delivers support in the 90 percent range. (Mitt Romney won 93 percent of his own party in 2012.) Trump's support among Republicans, according to the latest NBC News/Wall Street Journal Poll, was 86 percent.
And the snubs keep coming from the upper echelons of the party and the rank and file. In New Hampshire, the former senator Judd Gregg was initially a delegate for Bush. But when Bush suspended his campaign, Gregg became unbound. He has instead opted to skip the convention, telling a local television station, "Don't like large crowds."
The Indiana delegate who renounced his place at the convention, Claybourn, would have been bound to vote for Trump on the first ballot, a step he said he simply could not stomach.
"Donald J. Trump is the Republican Party's nominee," Claybourn said. "But he will not be my nominee and I will not attend a convention celebrating his candidacy."