Peter Wehner in The New York Times:
Beginning with Ronald Reagan, I have voted Republican in every presidential election since I first became eligible to vote in 1980. I worked in the Reagan and George H. W. Bush administrations and in the White House for George W. Bush as a speechwriter and adviser. I have also worked for Republican presidential campaigns, although not this time around. Despite this history, and in important ways because of it, I will not vote for Donald Trump if he wins the Republican nomination.
…Mr. Trump is precisely the kind of man our system of government was designed to avoid, the type of leader our founders feared — a demagogic figure who does not view himself as part of our constitutional system but rather as an alternative to it. I understand that it often happens that those of us in politics don’t get the nominee we want, yet we nevertheless unify behind the candidate who wins our party’s nomination. If those who don’t get their way pick up their marbles and go home, party politics doesn’t work. That has always been my view, until now. Donald Trump has altered the political equation because he has altered the moral equation. For this lifelong Republican, at least, he is beyond the pale. Party loyalty has limits. No votes have yet been cast, primary elections are fluid, and sobriety often prevails, so Mr. Trump is hardly the inevitable Republican nominee. But, stunningly, that is now something that is quite conceivable. If this scenario comes to pass, many Republicans will find themselves in a situation they once thought unimaginable: refusing to support the nominee of their party because it is the best thing that they can do for their party and their country.