Idaho GOP Sen. Mike Crapo isn't the type to make intraparty waves — so his decision to un-endorse Donald Trump cemented the Mormon insurrection against the Republican nominee.

Moreover, Crapo on Saturday morning became the first incumbent senator to reverse his support of Trump specifically due to the publication of lewd and sexually aggressive audio of Trump by the Washington Post on Friday. While Crapo is up for reelection this year, Idaho is one of the safest Republican states in the country — which means he probably could have still won reelection while supporting Trump.

Story Continued Below

"I have reached the decision that I can no longer endorse Donald Trump. This is not a decision that I have reached lightly, but his pattern of behavior has left me no choice," Crapo said on Saturday morning. "I urge Donald Trump to step aside and allow the Republican party to put forward a conservative candidate like Mike Pence that can defeat Hillary Clinton."

Trump's initial explanation that his 2005 back-and-forth with TV host Billy Bush was "locker room talk" was "unacceptable," Crapo said, "and is inconsistent with protecting women from abusive, disparaging treatment."

On Saturday morning the Utah delegation's opposition to Trump began to solidify. Rep. Mia Love (R-Utah) called Trump's latest comments a "new low" and concluded that she "cannot vote for him."

And the Deseret News, one of the state's largest newspapers, waded into presidential waters for the first time in its history. In an editorial, the paper deemed the Trump audio "evil" and called his behavior the "essence of a despot."

"We call on Donald Trump to step down from his pursuit of the American presidency," the paper declared.

The immediate rush by Mormon lawmakers like Love and Crapo marked the tip of the conservative spear against Trump, who has long been viewed with skepticism and downright opposition in some corners of the Mormon church. And it came before lawmakers in more competitive races began withdrawing their support, evidence that socially conservative voters have had enough of Trump.

Rep. Jason Chaffetz (R-Utah), another Mormon lawmaker, reversed his endorsement of Trump on live TV on Friday night.

“I’m out. I can no longer in good conscience endorse this person for president. It is some of the most abhorrent and offensive comments that you can possibly imagine,” Chaffetz told a Utah TV station.

Gov. Gary Herbert (R-Utah) and Sen. Mike Lee of Utah (R-Utah), other prominent Mormon politicians. also called for Trump to step aside on Friday evening. Herbert had previously endorsed Trump, while Lee had not.

"You, sir, are the distraction," Lee said in a video on Friday night. "I respectfully ask you with all due respect to step aside. Step down."

And on Saturday morning Sen. Jeff Flake (R-Ariz.), who has been pointedly critical of Trump while refusing to take a position in the race, said Trump is overestimating his own popularly by staying in the race and concluded that Trump "needs to withdraw."

Rep. Chris Stewart, another Mormon House Republican, said he is holding Trump "accountable" and is "calling for him to step aside and to allow Mike Pence to lead our party."

Sen. Orrin Hatch (R-Utah), a prominent Mormon political leader, has been critical of Trump but has not rescinded his endorsement.