Former House Speaker Kevin McCarthy’s announcement today that he will vacate his seat and not seek reelection sets off a tidal wave of speculation on who will represent a wide swath of California’s agricultural heartland. The timing of the announcement also puts McCarthy in a spot to be a political kingmaker if he makes an early endorsement. It’s a role he’s played before and relishes. In announcing his resignation in a Wall Street Journal op-ed, McCarthy reiterated that he will “continue to recruit our country’s best and brightest to run for elected office.” One thing is virtually certain: Mc…