After nearly a week-long firestorm surrounding Republican presidential nominee Donald Trump and his attacks on a federal judge because of his Mexican heritage, which led to harsh criticism from his supporters and even one un-endorsement, some Republicans are raising the specter that a new nominee could replace Trump.
Bob Vander Plaats, a supporter and campaign co-chair of former candidate Sen. Ted Cruz, suggested that a convention coup at next month's Republican nominating convention in Cleveland is possible.
"Everything's got to be on the table," said Vander Plaats, acknowledging to NBC News that could mean an effort to unbind the delegates from having to vote for Trump on the convention floor.
Vander Plaats said Trump's recent tirade against Judge Gonzalo Curiel is leading to "more and more questions going into Cleveland."
Conservative radio host Hugh Hewitt also vocalized a plan B on his radio program, saying that "the party ought to change the nominee — because we're going to get killed with this nominee."
But despite Vander Plaats and Hewitt's suggestion, two Republican National Committee rules committee members said they reject the notion, and Cruz's own top delegate aide quashed the idea on Wednesday.
Ken Cuccinelli, who worked as the Cruz campaign's top delegate wrangler, emphatically refuted, telling NBC News, that such efforts to change the party rules to defeat Trump won't happen. Cuccinelli continues to oversee an effort among Cruz loyalists to influence the platform and rules committees at the convention.
"That's not going to happen — at least among our people," Cuccinelli said. "I will say clearly we are not participating, and we are dissuading people from any effort to change the nominating effort in the rules committee."
But Trump opponents might not listen to efforts at dissuasion.
A.J. Spiker, the former national political adviser for Rand Paul's presidential campaign, backed a potential bid to overthrow Trump, calling on delegates to "vote their conscious" and "stop that man." He suggested Cruz naturally has the "most true support" among the delegates headed to Cleveland and that the campaign's infrastructure would not be far behind — if at all — what Trump's camp has tried to put together.
"I'd rather have the challenge of having to raise some money than having to pick up all the pieces that Donald Trump has smashed," Spiker said.
To change the rules, the RNC's rules committee — a body of 112 members — would have to vote by a simple majority in favor of unbinding the delegates, which would then require the approval of the entire convention delegation.
Even Vander Plaats, the president of the social-conservative group the Family Leader, noted the significant hurdle it would take to oust Trump in Cleveland. Because he is openly discussion the scenario is perhaps more symbolic of how damaging the last two weeks have been for Trump as some Republicans look for a way out from their previous support.
"Practically speaking, do we think it's even remotely possible that someone could come out of Cleveland other Trump?" Vander Plaats rhetorically asked. "It's highly unlikely, but it's been an exceptionally unprecedented election. And maybe the unprecedentedness continues."
Vander Plaats laid out his delegate math and how an open vote on the convention floor next month could play out in favor of Cruz.
"Of the delegates who were going to go, you're looking at a majority who were Cruz delegates," Vander Plaats said. "And the delegates who were going to attend the convention, for probably 500 or less, Donald was their first choice."
Asked whether Cruz would put himself up for the nomination in Cleveland, Vander Plaats said: "We know he was interested in being the nominee for president - it's a question of whether he or anyone would be open to accepting the mantle in that fashion."
Two Republican National Committee members, however, rejected the suggestion that an upheaval at the convention is plausible.
Morton Blackwell, an RNC committeeman and rules member from Virginia since 1988, told NBC News, flatly, that choosing someone other than Trump "wouldn't be fair" and would split the party.
"It would be a chaotic mess and stupid — it's a fantasy and will not happen," said Blackwell, who supported Cruz in the primary and calls him a personal friend. "There are too many sensible people involved."
Steve Scheffler, an RNC committeeman and rules member from Iowa, also disputed the notion that the rules committee would upend the primary and caucus results.
"The people of this country have spoken," Scheffler said. "Now is time to get on board and unify, and all these theatrics and doing something silly is not a smart thing to do."
Vander Plaats emphasized the desire for Trump to change but expressed nearly zero optimism in that outcome.
"Without some sort of a pivot point, like, 'Listen, I was wrong, and I'm going to repent and ask for forgiveness,' which doesn't seem to be coming anytime soon, we don't see that happening," he said.
This article first appeared on NBCNews.com.