My allegiance to the GOP was cemented during the 1980s, when I was in high school and college and Ronald Reagan was in the White House. For me, Reagan was what John F. Kennedy had been to an earlier generation: an inspirational figure who shaped my worldview. Reagan had his faults, like JFK, but he was optimistic and gentlemanly. He was pro-free trade and pro-immigration. He believed in limited government at home and American leadership abroad.

That’s what I believed in too — and that’s what I thought the Republican Party stood for. That’s why, despite my disagreements with social conservatives, I worked as a foreign policy advisor to John McCain in 2008, Mitt Romney in 2012 and Marco Rubio this year. All of those candidates, different as they were, recognizably represented Reagan Republicanism.

For the time being, at least, that Republican Party is dead. It was wounded by the tea party absolutists who insisted on political purity and rejected any compromise. Now it has been killed by Donald Trump.