The list of things Gov. Bill Haslam, and so many other Republicans, have been willing to stomach from their party's presidential nominee includes many, shall we say, deplorable episodes, but now we know what a mild-mannered billionaire from Knoxville just can't tolerate.

Since The Washington Post on Friday published a video of Donald Trump bragging with Billy Bush about how a star like him could grope women at will — "grab them by the pussy," even — a parade of elected Republicans have announced they will not vote for him and many have called for him to step aside as the party's presidential nominee.

On Sunday, just hours before the second presidential debate, Haslam joined them.

“In the past I have expressed my concern with Donald Trump’s policy positions. Like many others, I have also objected to many of the things he has said during his campaign. Those concerns have kept me from endorsing him."

“I want to emphasize that character in our leaders does matter. None of us in elected office are perfect, but the decisions that are made in the Oval Office have too many consequences to ignore the behavior we have seen.

“It is time for the good of the nation and the Republican Party for Donald Trump to step aside and let Gov. Mike Pence assume the role as the party’s nominee. If he does not step aside, I will write in a Republican for the Office of President.

“Finally, I want to urge Republicans to vote. Now more than ever, who we elect to Congress and our state and local offices is critical to the future of this country and state that we love.”

Haslam had never been an outward Trump supporter, so much as a sheepish silent bystander. He endorsed Sen. Marco Rubio in the Republican primary and has largely hemmed and hawed his way through the rest of the campaign, avoiding any definitive statements on whether he would vote for Trump. Not so for Sen. Bob Corker, who was named to Trump's security advisory council on Friday and has condemned Trump's comments but not withdrawn his support.

Haslam is the only Tennessee official to disavow Trump.