At Mt. Rushmore and the White House, Trump Updates ‘American Carnage’ Message for 2020

The searing tone he has adopted is in large part aimed at consolidating support within his own party. Private Republican polling indicates the president is slipping in red states, in large part because conservative-leaning voters are unsettled.

“Trump needs — or thinks he needs — fear of ‘the other’ to motivate his base and create enthusiasm,” said Christine Matthews, a Republican pollster. “Right now, people are fearful of Covid-19, but that is inconvenient for Trump, so he is trying to kick up fear about something he thinks will benefit his re-election: angry mobs of leftists tearing down American history.”

Ms. Matthews noted that his rhetoric does little more than solidify the voters who were already likely to return to his corner. “He has no interest at all in expanding his base or even pulling back in those who have departed,” she said.

Patrick Murray, the director of the Monmouth University Polling Institute, said that past presidents have typically sought to diffuse cultural battles, “giving people this amorphous kind of middle where they can continue to live.” Mr. Trump, however, is unlike any of his predecessors.

“Donald Trump does not give you that choice — you are either with him or against him,” said Mr. Murray, whose latest survey this week showed Mr. Biden leading 53 percent to 41 percent. “He is forcing people to take sides. And when they take sides, more of them are moving to the other side.”

In Mr. Biden, Mr. Trump also faces a centrist opponent who is not easily branded as a radical liberal, but rather one who is seen as a palatable alternative to some older voters and Republicans in a way that Hillary Clinton was not. Mr. Biden, for instance, has said he does not support defunding the police, and has made careful distinctions between tearing down monuments to the country’s founding fathers and those commemorating Confederate leaders.

That hasn’t stopped the Trump campaign from claiming that in the black-and-white world it wants to present to voters in November, Mr. Biden is on the side of violent looters. “The first instinct of Joe Biden and his party is to agree with the agitators that there is something fundamentally wrong with America and that there always has been,” Mr. Murtaugh said.