Donald Trump said the following — among many other nonsensical things — at a political rally in Michigan: “I know things about Tester that I could say, too. And if I said them, he’d never be elected again.”

What do you suppose they are?

I’m guessing they’re the kinds of “things” Trump said he knew about former President Barack Obama’s place of birth. Or about the “millions of illegal immigrants” who voted for Hillary Clinton in 2016. Or about the wiretap that President Obama ordered on his campaign office in New York.

Of course, the president produced not a shred of evidence for anything he said he had.

Now he’s threatening Sen. Jon Tester with “things” he allegedly knows. Tester’s sin? Oh, all he did was question whether Trump’s nominee to lead the Department of Veterans Affairs, Dr. Ronny Jackson, was fit for the job.

The Montana Democrat is not to blame for the president’s failure to vet Dr. Jackson properly before offering him as a VA secretary nominee. Tester isn’t to blame for Trump’s shabby and sloppy appointment process.

So now he’s threatening a U.S. senator? You know, I’m understanding better now what fired FBI Director James Comey means when he says Trump governs like a “mob boss.”

Disgraceful.