WASHINGTON — President Trump on Monday accused Democrats who did not clap during his State of the Union address of being un-American and even treasonous. His remarks came in a rambling, discursive speech at a factory in Ohio, during which he celebrated his revival of the American economy as the stock market plummeted by more than 1,000 points.

“Can we call that treason?” Mr. Trump said of the stone-faced reaction of Democrats to his speech. “Why not? I mean, they certainly didn’t seem to love our country very much.”

Mr. Trump was speaking during a visit to a company near Cincinnati that makes pneumatic and hydraulic cylinders. The company, Sheffer Corporation, awarded each of its 126 employees a one-time bonus of $1,000 after the passage of the tax cut, and the White House clearly hoped to use it to drive home the message of economic health in last week’s State of the Union speech.

“Your paychecks are going way up,” a beaming president said to this more friendly audience. “Your taxes are going way down.”