President Trump on Monday referred to former Vice President Joseph R. Biden as a “low I.Q. individual,” just days after he questioned whether former Rep. Beto O’Rourke’s fast-moving hand movements are a sign of mental instability.
As the 2020 Democratic field takes shape, the man they are aiming for is preparing his own suppressive fire in the same fashion he used so effectively against his 2016 opponents: ridicule.
“Joe Biden got tongue tied over the weekend when he was unable to properly deliver a very simple line about his decision to run for President,” Mr. Trump tweeted Monday. “Get used to it, another low I.Q. individual!”
That is an update from last year, when Mr. Trump tested out “Crazy Joe Biden” and called the former senator “weak, both mentally and physically.”
But then the “crazy” appellation is already taken for 2020, after Mr. O’Rourke drew Mr. Trump’s attention with his campaign announcement last week.
“I said, ‘Is he crazy or is that just the way he acts?’” Mr. Trump told reporters at the White House.
He also has used “crazy” on Sen. Bernard Sanders, a 2016 candidate who is taking another shot at the White House next year.
Though most voters say they wish the president would cut out the routine, Mr. Trump believes his method is a success after leaving “low-energy” Jeb Bush and “crooked” Hillary Clinton in the dust in 2016.
“Trump is very effective at saying things that people may have thought but would never have said,” Patrick Griffin, a Republican Party strategist, told The Washington Times. “At some level, nothing really digs in or works unless a few people can say, ‘Yes that is true.’”
Mr. Griffin said the president is channeling Don Rickles, a legendary comic who elevated insults into an art form.
Mr. Trump’s favorite target so far this campaign has been Sen. Elizabeth Warren, whom he has called “goofy” and dubbed “Pocahontas” in response to her claim of American Indian ancestry.
Indian leaders have called Ms. Warren’s dubious claims hurtful, but they also say Mr. Trump’s jibe is insulting.
Yet the president revels in it. He fretted earlier this year that he may have deployed the nickname too soon.
“Because I’ve destroyed her political career, and now I won’t get a chance to run against her, and I would’ve loved it,” he said at the Conservative Political Action Conference.
Scott Ferson, a Democratic strategist in Massachusetts, said the attack against Ms. Warren is over the top but effective because it plays off a lingering “kernel of doubt in voters’ minds.”
“So by harping on the ‘fake Indian’ line, he is tapping into what I think voters are concerned with in terms of just her believability and trustworthiness,” Mr. Ferson said. “There is that little bit of doubt as to how she handled her professional life, and she has never been able to put that to bed — and he keeps scratching that scab.”
Mr. Trump puts some thought into it, according to an Associated Press report last month, which said the president was test-driving labels.
At root, the insults play into Mr. Trump’s role as critic in chief, commenting on pop cultural elements such as “Saturday Night Live” and former celebrity friends. The common factor is that they have been antagonistic toward him.
“The bottom line is that he personalizes politics in a way that most of those involved in it do not, mostly because they are invested in the system — and therefore want to preserve their options in the event they lose,” said Mike McKenna, a Republican Party strategist. “He is not invested in the system and therefore doesn’t really care about whose feelings he hurts.
“That’s what drives people bananas,” he said. “He refuses to play by the rules, customs and traditions. They have no clue what to do with him.”
Past targets included 2016 primary opponents Sen. Marco Rubio and Sen. Ted Cruz, who were given the monikers “Little Marco” and “Lyin’ Ted.” Mr. Trump made sure to let his audience know “Lyin’” was said with an apostrophe.
Mr. Cruz countered that Mr. Trump was “a sniveling coward.”
Since then, Mr. Cruz has earned his way out of the Trump doghouse and is now dubbed “Beautiful Ted.”
Mr. Ferson said Democrats must avoid taking Mr. Trump’s bait. TV news anchors and commentators air every word, even as they tsk tsk the president.
“If Democrats are going to be successful, we will have to figure out how to ignore him without ignoring him,” Mr. Ferson said. “It means when you are constantly asked by media about what the president has said about you, we have to find a way to more effectively get a message out in that exchange.”
That is easier said than done, he said.
“You wouldn’t pay attention to Donald Trump if he were your friend, but he is not your friend. He is the president of the United States,” he said.