CAN THE REPUBLICAN PARTY SURVIVE DONALD TRUMP?

The past two times the G.O.P. has suffered an election loss—and, going by the week so far, sorry, Republicans, it’s headed for another—one faction has said the party needs to moderate its politics and move to the left, while another faction has said the party needs to offer true conservatism and move to the right. Donald Trump, an accidental radical, thinks both sides are wrong and has campaigned on that basis, going both ways at once. He has moved the party to the right with outlandish counter-terrorism proposals, but he...