Michael Bloomberg once was thought to be considering a run for the presidency in 2020.

Then he said “no,” he wouldn’t be a candidate for the White House.

Oh, but wait! Now he’s back in, sort of.

The former New York City mayor has announced his intention to file for the Alabama Democratic primary. It seems that Bloomberg is unhappy with the slate of Democrats battling for their party’s nomination and the right to do battle with Donald J. Trump.

My request of the ex-mayor is this: Don’t do it!

I want a candidate with a set of principles and a commitment to governing. I am not interested in considering someone who is dissatisfied with the candidates who already have made that leap of faith and are asking Americans to join them in that leap.

It’s not that Bloomberg is a fringe player. He’s a mega-rich guy. He has been a registered Republican, a registered Democrat and a registered independent. I don’t know what he considers himself at this moment. That he is going to file in the Alabama Democratic primary tells me he is now a Democrat … for the time being.

I get that the Democratic field so far hasn’t excited a lot of folks. I have problems with every singe one of them still in the fight. None of the problems I have with the Democratic contenders, though, matches the profound loathing I feel for the Republican who is running for re-election as president.

My queasiness with Bloomberg, though, is based on his in-out-maybe-back-in posture. Is he committed to governing or is just interested in making some sort of media splash?

Stay out of the race, Mr. Mayor.