The Indiana’s governor’s race should not, under normal circumstances, be remotely competitive. In 2020, Donald Trump won the state by 16 percentage points, and the current Republican governor, Eric Holcomb, won by more than 20. All the state’s leading officials are Republicans, and the party has supermajorities in both legislative chambers.

But after the Republican convention this weekend, the influential conservative lawyer James Bopp Jr. wrote, in a confidential memo obtained by Politico’s Adam Wren, that there’s a “serious threat” to the party’s nominee for governor, Senator Mike Braun.

That threat is Micah Beckwith, a Pentecostal pastor, podcaster and self-described Christian nationalist who was just chosen, despite Braun’s wishes, to be his running mate. Ordinarily, The Indianapolis Star reports, convention delegates rubber-stamp their candidate’s choice of lieutenant. But this year, they rebelled, rejecting Braun’s selection, a state representative named Julie McGuire, for Beckwith, who embodies the combative spiritual fervor ascendant among the party’s grass-roots. As a result, wrote Bopp, “Democrats have a real opportunity to launch a serious campaign in the fall because of Beckwith’s nomination, and it has already begun.”

Democrats will have plenty of material to work with. The day after the Jan. 6 insurrection, Beckwith said that God had told him: “Micah, I sent those riots to Washington. What you saw yesterday was my hand at work.” He’s said that the “progressive left has taken over the Republican Party in Indiana,” and promised that if he wins, he’ll be a thorn in the side to the governor.

Before his victory this weekend, Beckwith was probably best known for leading a campaign to purge the young-adult shelves at the Hamilton East Public Library, where he was a board member until January. (He resigned after a policy he’d promoted, which removed books that included sex, violence or repeated profanity from a section for teenagers, was reversed.) Braun, wrote Bopp, will be “made to answer” for every statement Beckwith has ever made.

Beckwith’s elevation is the latest sign of a conflict splitting Republican parties nationwide, as G.O.P. activists demand ever greater levels of purity and belligerence from their leaders. I’ve written about this in Minnesota, where delegates to the state convention endorsed the Alex Jones acolyte Royce White for Senate, and in Colorado, where the state party recently called for the burning of Pride flags. Cadres of true believers inspired by Donald Trump, and by the religious movement that sees him as divinely ordained, are seizing the party from the bottom up, much to the consternation of more traditional Republicans who thought they could indulge the MAGA movement without being overtaken by it.