Perhaps this shouldn’t be a surprise: If they did care about the same things that animated “very liberal” voters, they probably would have gone to the polls in these crucial states. Eighty-six percent of very liberal registered voters turned out in either 2016 or 2018 in these states, the highest percentage of any ideological group.

That said, there are some signs that Democratic-leaning nonvoters are somewhat likelier to favor a bold candidate who offers something different. In no small part because of their relative youth, they say they would prefer a candidate who promises fundamental, systematic change to American society over one who promises to return Washington to normal. I n contrast, Democratic-leaning voters who turned out in both 2016 and 2018 prefer a return to normal.

Young nonvoting Democrats are slightly more likely than young voting Democrats to support fundamental, systematic change over a return to normal. But in keeping with the broader pattern, they offer more conservative answers on the issues than those who vote.

The gap is particularly stark on cultural questions. Among people under 30 who lean Democratic, the nonvoters are far more likely than the voters to agree that the women who are running for president “just aren’t that likable.”

The pattern also extends to issues like immigration or health care. Over all, the young Democratic nonvoters are far less likely to describe themselves as very liberal.

From all this, you could stitch together a case that Democrats have struggled to appeal to less educated nonvoters, particularly among those who are young and black. These nonvoters do not like the president and they are not conservatives, but they do not appear to have been socialized into the cultural norms of the party’s liberal college-educated coastal base. As a result, they have not responded to the president’s conduct with the urgency and outrage of their peers. And some of them may even dissent from their generation’s progressive consensus on cultural issues.

When it comes to the candidates, Mr. Sanders shows relative strength among nonvoters: He has a 41 percent “very favorable” rating in the group, compared with 33 percent for Mr. Biden and 30 percent for Ms. Warren. This is at least in part because of Mr. Sanders’s longtime appeal to young voters.