Harris holds a 50%-47% lead over Trump in a Cooperative Election Study survey released this week, part of a national study by universities that was conducted by YouGov (1,542 respondents).

Trump has a narrow one-point advantage in an Emerson College poll of likely voters released Thursday (margin of error 3.4), while the candidates are tied in two other surveys out last week: a Quinnipiac poll that found them both with 48% support and a Bloomberg/Morning Consult poll that shows Trump up 48.3%-48%.

Harris is up three points, 50% to 47%, in a Washington Post-Schar School poll of likely voters released last week (margin of error 4.6), and an early October Wall Street Journal poll showed them tied at 48% among registered voters.

Most polls of Wisconsin—whose 10 electoral votes could prove crucial—reflect a razor-thin race, with Harris leading by just 0.3 points in FiveThirtyEight’s weighted average.

A Marquette Law School poll released Oct. 2 found Harris up six points over Trump in the state and that enthusiasm for voting has ticked up sharply, with 67% of respondents saying they are “very” enthusiastic, compared to 46% who said so in June; enthusiasm among Wisconsin Democrats is slightly higher, with 71% saying they are very enthusiastic and 67% of Republicans saying they’re very enthusiastic.

Voter turnout in Wisconsin could be high in November as there are several competitive U.S. House races in the state on the ballot and Republicans are in a tight contest to maintain majority control of the state Assembly, Anthony Chergosky, an assistant professor of political science at University of Wisconsin-La Crosse told WUWM public radio in Milwaukee.

Waning support for Democratic Sen. Tammy Baldwin in the Wisconsin Senate race is also seen as a warning sign for Democrats as Cook Political Report moved the state from lean Democrat to a toss-up last week after finding her lead over Republican Eric Hovde has shrunk from seven points to two since August, though a Marquette Law School poll, also released last week, still found her with a seven point advantage.

Biden won Wisconsin by less than one point in 2020, flipping the state after Trump beat Hillary Clinton there in 2016; former President Barack Obama won the state by decisive margins in both 2008 and in 2012.