Harris Has a Polling Edge in Wisconsin, but Democrats Don’t Trust It

The vice president, who is visiting the state on Friday, has led Donald Trump there more often than not. Yet nearly everyone in Wisconsin politics believes the race will be incredibly close.

On paper, Vice President Kamala Harris should be feeling hopeful about Wisconsin.

The last 40 public polls included in The New York Times polling average of the vital battleground state show her leading in 28, tied in four and trailing former President Donald J. Trump in eight.

Ms. Harris, who is set to hold a rally in Madison on Friday evening, was up by four percentage points in the latest survey from Marquette Law School, widely considered the gold standard of Wisconsin polling. The Times polling average has shown her leading every day, albeit narrowly, since Aug. 6.

And yet, in what has appeared to be Democrats’ strongest battleground state even when President Biden was still in the race, Democrats, Republicans and even the state’s pollsters can agree on one thing: They don’t fully trust the polling and don’t believe Ms. Harris is ahead by as much as some of the surveys say.

“My numbers are my numbers, but I think in terms of putting it into context, four points would be a surprisingly strong finish for Harris,” said Charles Franklin, who conducts the Marquette Law School poll and began a new survey of the state this week. “That would be a huge margin for Wisconsin.”

Indeed, just about anyone involved in Wisconsin politics can recite the state’s history of close calls. Four of its last six presidential races were decided by fewer than 25,000 votes — less than a percentage point. When Gov. Tony Evers, a Democrat, won re-election two years ago by 3.4 points, it was considered a blowout. On that same ballot, Senator Ron Johnson, a Republican, defended his seat by fewer than 27,000 votes, 1 percent of the vote.

Even though the Democratic Party and its allied candidates have won 12 of the last 15 statewide elections in Wisconsin, there remains a widespread sense that polling data should be viewed skeptically and that voters who support Mr. Trump are quietly waiting to vote in large numbers.

“After Hillary’s first debate in 2016, she was the clear winner back then, there was no question about it,” said Sarah Godlewski, the Wisconsin secretary of state, who served as Hillary Clinton’s deputy political director for the state that year. “The voters that Donald Trump is going to turn out are going to be first-time voters that we have no data on and don’t even know about. You can’t poll people that you don’t even know about.”

Many polls show the race to be extremely close. Two released this week, from Marist College and Quinnipiac University, found Ms. Harris with a smaller lead, just a point. A survey from Emerson College and The Hill, a Washington newspaper, showed Mr. Trump up by one point.

Still, Wisconsin Republicans have often been on the defensive lately. Their state party is a shell of the powerhouse that swept into office in the 2010s and made household names out of Gov. Scott Walker, Speaker Paul D. Ryan and Reince Priebus, who went from state party chairman to Republican National Committee chairman to White House chief of staff. Much of the party’s get-out-the-vote effort is now being run by independent groups to which the Trump campaign has outsourced much of its ground game.

Yet there is optimism that things may be OK for Mr. Trump and Wisconsin Republicans.

“I’m never overconfident,” Senator Johnson said in an interview on Wednesday. “But I never believe the polls.”

Mr. Johnson, who was a leading proponent of false claims about the legitimacy of the 2020 election, said his optimism was based on a doubtful supposition that the 2024 contest would be on the level. He said he was worried about undocumented immigrants voting — though not as worried as he was that they would vote in other battleground states.

(Only U.S. citizens are allowed to vote in American presidential elections, and there is no evidence that noncitizens, let alone undocumented immigrants, participate in elections beyond a sparse number.)

“It’s as obvious as the nose on anybody’s face that Democrats want to make it easy to cheat and make it easy for illegals to get registered and to vote,” Mr. Johnson said. “When Republicans win, I think it’s legitimate, because we don’t cheat.”

Brian Schimming, the chairman of the Wisconsin Republican Party, said there was some credence to Democratic fears about a hidden group of potential G.O.P. voters waiting in the shadows to vote for Mr. Trump. Republicans now have 41 offices across the state, he said.

“There’s hundreds of thousands of people in this state that think like us, act like us, believe like us, and live like us, and they don’t vote,” Mr. Schimming said. “I’ll always ask people in a crowd if they know that person, and all the hands go up.”

While polling shows Ms. Harris and Mr. Trump neck and neck, the state’s Senate race has tightened from where it was over the summer. Marquette’s latest poll showed Senator Tammy Baldwin, a Democrat, with the same four-point lead over Eric Hovde, her Republican challenger, that Ms. Harris had over Mr. Trump.

When Mr. Biden last visited Madison in July, Ms. Baldwin held her own campaign event three hours away in Marinette, a small town on Wisconsin’s border with the Upper Peninsula of Michigan. By contrast, she is expected to speak on Friday at Ms. Harris’s rally and then spend the weekend campaigning in southwestern Wisconsin with Gov. Josh Shapiro of Pennsylvania, a top Harris ally.

Much of the advantage that Ms. Harris and Ms. Baldwin have comes from a well-funded state party apparatus widely acknowledged as the Democrats’ best in the country. Demographic shifts have also helped the party, including a population boom in Madison, the state capital, which serves as the heartbeat of Wisconsin’s Democratic base.

Ms. Harris is planning to arrive in Madison after a Friday morning stop in Atlanta to emphasize Mr. Trump’s opposition to abortion rights.

“In Madison, the more you stress the threat of what Donald Trump can do, it’s probably better,” said Representative Mark Pocan, a Democrat who represents the city. “You have more people who care about democracy here than elsewhere, where cost of living and other issues resonate more.”

But Democrats in the state have long memories of not only 2016, when Mr. Trump won, but also of 2020, when a poll from The Washington Post and ABC News two weeks before the election showed Mr. Biden with a 17-point lead in the state over Mr. Trump, in a race that was ultimately decided by less than one point.

“The hope,” said Ben Wikler, the Wisconsin Democratic chairman, “is that we don’t have a giant polling miss when the polls say that we are one point up.”