Americans Are Afraid. Not for Themselves, but for the Country.

She knows that Pennsylvania could be pivotal to the outcome of the election, and that the president has repeatedly disparaged Philadelphia. She worries that the protests there in the election’s final days could discourage African-Americans from voting, or that jailed protesters will be unable to cast a ballot. She, too, has never felt this anxious.

“I have more fear in 2020,” she said, “because I really see us falling over a cliff.”

The fears that Tom Scribner holds won’t be fixed by this election, he said. Mr. Scribner, a 36-year-old Hispanic voter in Gainesville, Fla., doesn’t believe the country holds the same values it did when he enlisted in the Marine Corps at 18. He opposes defunding the police and removing the statues of Confederate generals and founding fathers, and he feels disrespected as a veteran by athletes who kneel during the national anthem. He worries that his two children will grow up walking on eggshells in America, for fear of saying the wrong thing.

He plans to vote for Mr. Trump. But he doesn’t believe any one president or election can alter underlying shifts in American values.

“That’s why I fear for our democracy,” Mr. Scribner said. “I feel like it may just crumble. It may not happen in the next four years. It may take 20 years for it to happen, and it’s going to be chaos for however long until it does. That saddens me deeply.”

In earlier moments of anxiety about democracy itself, reforms followed, said Professor Gage, the historian. When Americans grew anxious about corrupt political machines and concentrated economic power in the early 20th century, what followed were civil-service laws, new political primaries, the direct election of senators and voting rights for women. Out of the 1960s, the voting age was lowered so Americans old enough to be sent to war would also be old enough to vote. And political primaries were reformed again to give voters more say in the nominees.

It’s unclear whether something similar will happen this time.

“If people have actually lost faith in the idea that you can fix things and make them better,” Professor Gage said, “then that’s not a great political moment to be in.”

Here are the crosstabs for the poll.