President Trump has a proclivity for tweeting, typos and trenchant nicknames.

In making use of the first habit on Sunday, he alluded to a profanity — and left many wondering which of his other online idiosyncrasies were at work.

In the tweet, the president took aim at Representative Adam B. Schiff of California, a Democrat who is the incoming chairman of the House Intelligence Committee. Mr. Schiff has said that Democrats would investigate Mr. Trump’s acting attorney general, Matthew Whitaker, who is charged with overseeing the Russia investigation led by the special counsel, Robert S. Mueller III.

“So funny to see little Adam Schitt (D-CA) talking about the fact that Acting Attorney General Matt Whitaker was not approved by the Senate, but not mentioning the fact that Bob Mueller (who is highly conflicted) was not approved by the Senate!” Mr. Trump tweeted.

The post quickly set off reactions on social media, as some critics assumed that the president had deliberately misspelled the congressman’s name to make it sound like a vulgarity.

