The fight isn’t really between two men. It’s between two takes on what matters most in this messy world. I might as well be blunt: It’s between the high road and the gutter. McCain has always believed, to his core, in sacrifice, honor and allegiance to something larger than oneself. Trump believes in Trump, and whatever wreckage he causes in deference to that god is of no concern.

“Trump is in every single way the opposite of John McCain,” Bob Kerrey told me recently. “He may be the opposite of every president we ever had.” Kerrey and McCain both served in Vietnam, they overlapped in the Senate and they stay in touch. So Kerrey knows that Trump has caused McCain no small measure of anguish, but less because of Trump’s crassness and the daily tragicomedy of his administration — this, too, shall pass — than because of “the impact on democracy.” It could be enduring, and it could be profound.

That’s why a patriot like him could never sit this one out.