What did Donald Trump do today?

He got into a public pissing match with the adult film actress he cheated on his wife with.

Trump had no public events on his schedule today, which left him free to spend most of the day on Twitter. He made 20 tweets by 10:00 P.M. EDT. One of them was a riff on the news that one of Stormy Daniels' lawsuits against him had been dismissed.

Daniels, whom Trump voluntarily paid $130,000 to not discuss their sexual encounter, responded in kind:

The "letter" Trump is referring to is a statement Daniels made when her non-disclosure agreement with Trump was still in force. She first told In Touch magazine about her affair with Trump in 2011, long before his political career began. (Trump's "fixer" Michael Cohen has since pleaded guilty to campaign finance law violations in association with that hush money payment, which was made days before the 2016 election.)

Trump's threat of a countersuit is probably not giving Daniels much anxiety. Not only would he have to testify under oath in any civil suit, he almost never follows through on his threats to bring libel suits, and has never prevailed on the rare occasions he's actually gone to court.

Why should I care about this?

• Traditionally, most presidents have been able to get through the day without publicly calling their porn star ex-mistresses names.

• A president who had a reasonable, non-incriminating explanation for a mysterious six-figure payment to a porn star would have given it by now.