I think jgw, that the evangelicals, the white born again Christians are the ones with power. That power resides in the Republican Party only. According to the 2020 exit polls, they made up 28% of the electorate or those who voted in 2020, they voted for Trump by a 76-24 margin. They’re a reliable republican vote, stands to reason they would be a most powerful block or faction within the GOP. 28% isn’t going to win any elections, you must add to that reliable core. I suspect their power, certainly a force within the GOP primaries to be reckon with, not so much in the general election.
Each party has certain groups that are reliable voters for their candidates and supporters of issues dear to each party. Each group votes for the party that serves their own self-interests. Republican candidates know that they must win over the white born again evangelicals in order to gain their party’s nomination