The day after F.B.I. agents searched his home in Mar-a-Lago, former President Donald J. Trump yet again illustrated his electoral pull on the Republican Party. In a series of primaries in Wisconsin, Minnesota, Vermont and Connecticut on Tuesday — and in a newly conceded race from last week’s election in Washington State — Mr. Trump’s candidates scored victories and his enemies drew defeats, with a notable exception. In a series of primaries in Wisconsin, Minnesota, Vermont and Connecticut on Tuesday — and in a newly conceded race from last week’s election in Washington State — Mr. Trump’s candidates scored victories...