The editor of one of the conservative establishment’s most influential magazines is now lashing out at the nation’s most prominent right-wing newspaper editorial board over whether conservatives should run a third-party candidate if Donald Trump is the Republican presidential nominee.

With Trump on the verge of clinching his party’s nomination, the conservative movement is in shambles. Dozens of right-wing commentators have come forward to say that they will never vote for Trump, either due to his bigotry and authoritarian tendencies or because of his alleged progressive positions. Those conservatives have said they will stay home, vote for the Democratic candidate, or support a third-party candidate.

Bill Kristol, the editor of the Weekly Standard and a prominent conservative activist who bears significant responsibility for Sarah Palin ending up on a national ticket, is part of that faction. In February, he said that he “would try to recruit a real conservative” to run an independent campaign if Trump became the Republican nominee.

But a large group of conservatives are either openly rooting for the New York businessman or have come to terms with the likelihood that he will be their party’s standard-bearer.

The Wall Street Journal’s editorial board joined that final group this morning, with a piece criticizing any effort to enlist a third-party candidate (Rupert Murdoch, the paper’s owner, has said that the party would be “mad not to unify” around Trump). The editors write:

Readers know our doubts about Mr. Trump, on policy and as an autumn candidate. His nomination still isn’t guaranteed, and the polls show him badly trailing Mrs. Clinton, despite her many flaws. Third-party advocates say the right candidate would give conservatives an honorable alternative to Trump-Hillary. They say a third-party candidate could win enough states to throw the election into the House of Representatives, which would then presumably choose the non-Trump Republican.

This isn’t impossible, but then again it almost never happens. The usual presidential result is that the party that splinters hands the election to the other, more united party. 

The editors conclude that a third-party conservative candidate would be devastating to the party’s House and Senate candidates: “[D]ueling presidential candidates would put House and Senate Republican candidates in a perilous spot. Do they support Mr. Trump or the third-party conservative? If they are forced to choose, they could alienate enough GOP voters to ensure defeat.”

Hours later, Kristol threw down the gauntlet at the Journal. Pointing to Trump’s “crazed” comments this morning linking Sen. Ted Cruz’s father to the assassination of John F. Kennedy, Kristol declared that “serious people, including serious conservatives, cannot acquiesce in Donald Trump as their candidate.”

Kristol savaged the Journal for prioritizing “political prudence,” concluding that regardless of the political implications, “Donald Trump should not be president of the United States. The Wall Street Journal cannot bring itself to say that. We can say it, we do say it, and we are proud to act accordingly.”

The Journal and Kristol may both be right: Giving conservatives no choice but to support Trump in the general election may be better for the party’s congressional candidates (though it also makes it impossible for them to distance themselves from their incredibly unpopular nominee). But supporting Trump in spite of what the Journal gingerly describes as their “doubts” about his candidacy is quite obviously an act of raw political cowardice.

It’s only May, and the looming Trump candidacy is already dividing even the establishment’s stalwarts. Who knows what the next six months will bring. But it will surely be fun to watch from the outside.