It’s instructive to look at what prompted the flop-sweat panic of recent days. After leaving the Republican National Convention in Cleveland, Trump climbed the rhetorical jackass tree and then hurled himself earthward, hitting every branch on the way down.

There’s not enough space here to recount in any serious detail all of the self-destructive statements and bizarre rabbit holes he spelunked into — from attacking the parents of Captain Humayun Kahn, a soldier who died serving our country, to “jokingly” inviting the Russians to muck about in our elections, to reviving past controversies about Senator Ted Cruz’s father’s alleged complicity in the Kennedy assassination.

And yet GOP establishment leaders stuck with their man — just as they’d stuck with their man when he threw NATO under the bus, and ridiculed our treaty obligations with Japan, and attacked American-born Judge Gonzalo Curiel for an alleged conflict of interest between his professional duties and his Mexican heritage. (Sure, House Speaker Paul Ryan and others criticized Trump’s comments, but they did not officially distance themselves from him.)

GOP leaders contemplated pulling the emergency brake on the Trump Train only when the nominee said he wouldn’t endorse Ryan or senators John McCain and Kelly Ayotte.

The message was clear: Only his willingness to endanger top Republicans’ reelection was truly unacceptable behavior. Nothing else Trump said or did until then was beyond the pale.