In the waning days of an extraordinary political summer, Vice President Kamala Harris is ahead of former president Donald Trump in Pennsylvania and two other critical battleground states that previously seemed to be slipping out of reach for Democrats, according to new surveys of likely voters by the New York Times and Siena College.

The findings suggest that the presidential race remains tight, and also that the dynamics of a contest many voters saw as stale and lifeless have been fundamentally altered with less than 100 days to go.

Harris leads Trump by four percentage points, 50% to 46%, among likely voters in Pennsylvania, Wisconsin and Michigan, according to the new polls. The surveys were conducted among a representative sample of registered voters in the three states from Aug. 5 to 9. The margin of error is between 4 and 4.5 percentage points.

The findings capture an election still in flux: Harris announced that Minnesota Gov. Tim Walz would be her running mate a day into the polling, on Aug. 6.

Still, the results are significant because nearly a year of polls showed a dead heat between Trump and Biden, with Trump gaining ground in recent months. The new polls reflect increased enthusiasm across both parties in a previously weary electorate: In May, 58% of voters said they were satisfied with the presidential candidates they had to choose from. In August, that percentage jumped by 15 points.

Among likely voters in Pennsylvania, Harris leads Trump 50-46, with voters naming the economy, abortion, and immigration as the top three issues motivating them to vote. A majority of those likely voters said they believed Trump would be better on the economy and immigration, while Harris would be better on abortion and democracy.

In Pennsylvania, Trump maintains a strong advantage among white voters with no college degree, and voters in the center of the state. Harris leads among nonwhite voters, white voters with a college degree, and voters in the greater Philadelphia area and Allegheny County, which includes Pittsburgh.

In the Pennsylvania Senate race, likely voters showed a strong preference for Democratic Sen. Bob Casey over Republican challenger Dave McCormick, with Casey leading by 14 percentage points.

Since Joe Biden dropped out of the race and endorsed Harris on July 21, Harris has seen a spate of positive media attention, raised millions of dollars, and packed stadiums across the country. Trump has referred to it as “Harris’ honeymoon,” and predicted it will end. The feeling of positivity toward Harris is reflected in the latest poll: Her favorability rating increased by 10 percentage points among registered Pennsylvania voters in the last month.

The dust has not yet settled, but the fundamentals of the race are already drastically different than they were just a few months ago. In May, Trump led Biden by 3 percentage points in a two-way race, within the margin of error of a survey of registered voters in a Philadelphia Inquirer/New York Times/Siena College poll. At the time, voters expressed concerns over the economy and voiced that they were eager for change. Support for Biden in May was eroding among young voters and nonwhite voters, and Biden’s age was a large and growing issue.

As Benjamin Duerr, a 29-year-old electrician from Upper Darby who planned to vote for Biden, told The Inquirer at the time, “I just feel like Biden’s pretty incompetent … But he won’t f— up things too much, you know?”

In the new August polls, a majority of registered voters across the three states said Harris, more than Trump, has the temperament to be an effective president, and more said Harris was “intelligent.” A striking 81% of registered voters said they were enthusiastic to vote.