Mr. Trump has the support of 59 percent of white voters, up from 53 percent in our last poll. Nearly 90 percent of Republicans back him as well, up from just 80 percent after the final debate.

Mr. Trump even leads among well-educated white voters, who backed Mrs. Clinton in our first two polls of the state. It’s a similar story: Mr. Trump now holds the support of about half of white voters with a college degree, while Mrs. Clinton remains unchanged at 41 percent.

To win, all three Republicans on the ballot will need a strong showing on Election Day. More than three million North Carolinians have cast their ballots, about two-thirds of the likely electorate.

Mrs. Clinton leads among voters who have already cast their ballot by a nine-point margin, 49 percent to 40 percent. But Mr. Trump leads among those yet to vote by 17 points, 52 percent to 35 percent.