The polls have shown Donald Trump with an edge for eight straight months, but there’s a sign his advantage might not be quite as stable as it looks: His lead is built on gains among voters who aren’t paying close attention to politics, who don’t follow traditional news and who don’t regularly vote.

Disengaged voters on the periphery of the electorate are driving the polling results — and the story line — about the election.

President Biden has actually led the last three New York Times/Siena national polls among those who voted in the 2020 election, even as he has trailed among registered voters overall. And looking back over the last few years, almost all of Trump’s gains came from these less engaged voters.

Importantly, these low-turnout voters are often from Democratic constituencies. Many back Democratic candidates for U.S. Senate. But in our polling, Biden wins just three-quarters of Democratic-leaning voters who didn’t vote in the last cycle, even as almost all high-turnout Democratic-leaners continue to support him.

This trend illustrates the disconnect between Trump’s lead in the polls and Democratic victories in lower-turnout special elections. And it helps explain Trump’s gains among young and nonwhite voters, who tend to be among the least engaged.