House Majority Whip Kevin McCarthy (R-Calif.), an easygoing Californian and former recruiter of conservative candidates, is best positioned to take Cantor’s place, regardless of when he leaves. McCarthy has a deep well of support and a light managing style that has won favor with the conference’s younger and more independent members. He was a co-author of “A Pledge to America,” the GOP’s 2010 election manifesto and seen as an able communicator. But his at times rocky experience on the floor, where he has seen some major votes fail after being whipped and some conservatives unhappy with his tactics, has raised questions about his leadership.