Trump Rally Underscores G.O.P. Tension Over How to Win in 2022

PHOENIX — Former President Donald J. Trump returns on Saturday to Arizona, a cradle of his political movement, to headline a rally in the desert that will be a striking testament to how he has elevated fringe beliefs and the politicians who spread them — even as other Republicans openly worry that voters will ultimately punish their party for it.

Mr. Trump’s favored candidate for governor, Kari Lake, is a first-time office seeker who has threatened to jail the state’s top elections official. His chosen candidate to replace that elections official, a Democrat, is a state legislator named Mark Finchem, who was with a group of demonstrators outside the Capitol on Jan. 6 as rioters tried to stop the certification of the 2020 election. And one of his most unflinching defenders in Congress is Representative Paul Gosar, who was censured by his colleagues for posting an animated video online that depicted him killing a Democratic congresswoman and assaulting President Biden.

Mr. Trump has invited all three to join him onstage on Saturday for an evening that promises to be full of political revelry and retribution, marking the former president’s unofficial debut in a midterm election year in which he will try to exert a heavy hand.

But as popular as the former president remains with the core of the G.O.P.’s base, his involvement in races from Arizona to Pennsylvania — and his inability to let go of his loss to Mr. Biden — has veteran Republicans in Washington and beyond concerned. They worry that Mr. Trump is imperiling their chances in what should be a highly advantageous political climate, with Democrats deeply divided over their policy agenda and Americans taking a generally pessimistic view of Mr. Biden’s leadership a year into his presidency.

Senator Mitch McConnell, the Republican leader, and other senior party officials have expressed their misgivings in recent days about Mr. Trump’s fixation on the last election, saying that it threatens to alienate the voters they need to win over in the next election in November.

Those worries are particularly acute in Arizona, where the far-right, Trump-endorsed slate of candidates could prove too extreme in a state that moved Democratic in the last election as voters came out in large numbers to oppose Mr. Trump. The myth of widespread voter fraud is animating Arizona campaigns in several races, alarming Republicans who argue that indulging the former president’s misrepresentations and falsehoods about 2020 is jeopardizing the party’s long-term competitiveness.

“I’ve never seen so many Republicans running in a primary for governor, attorney general, Senate,” said Chuck Coughlin, a Republican consultant who has worked on statewide races in Arizona for two decades. “Usually you get two, maybe three. But not five.”

For Republicans who are concerned about Mr. Trump’s influence on candidates they believe are unelectable, the basic math of such crowded primaries is difficult to…