WWith less than three weeks until Election Day, Vice President Kamala Harris is directing her offer to a core group of voters who could help flip a coin-flip election: anti-Trump Republicans.

In a speech backed by Republican supporters on Wednesday and an interview on Fox News that evening, Harris attempted to invite disaffected conservatives into her coalition. Speaking in Bucks County, Pennsylvania, not far from where George Washington crossed the Delaware River, the Democratic candidate urged them to put country above party and unite against an opponent who disrespects the U.S. Constitution .

“At stake in this race are the democratic ideals for which our founders and generations of Americans fought. “The Constitution itself is at stake in this election,” Harris said, along with more than 100 Republicans from Pennsylvania and other swing states.

Donald Trump “views any American who does not support him or bow to this will as an enemy of our country,” Harris said. “It is clear: Donald Trump is becoming increasingly unstable and unhinged and is seeking uncontrolled power.”

Since Trump was elected in 2016, Democrats have hoped that Republicans would abandon a politician who trampled on many of their party's core ideals. It didn’t happen – at least not in significant numbers. Still, Harris believes there are enough conservatives who have serious doubts about Trump that winning them over could be enough to produce a close election.

Read more: What kind of president would Kamala Harris be?

There is evidence that the strategy could work. More than 150,000 Republican voters voted for Nikki Haley in Pennsylvania's GOP primary, weeks after she dropped out of the race. President Biden only won the state by about half that number in 2020. According to Haley Voters for Harris, a SuperPAC that aims to persuade center-right voters to vote for Harris, the number of people who voted for former South Carolina Gov. Nikki Haley in the 2024 GOP primary is , both before and after she leaves the race, is enough to sway battleground states like North Carolina, Georgia and Arizona. “The number of people who voted for Haley after she dropped out of the primary, particularly in places like Pennsylvania, is a potentially crucial vote count,” said Craig Snyder, a former GOP congressional chief of staff who now directs Haley Voters for Harris directs.

Haley herself has since supported Trump. However, according to a Blueprint poll, a significant portion of her voters remain against him: Only 45% of Haley voters now say they will vote for Trump, while 36% say they will vote for Harris. Nearly 20% remain undecided, and those are the voters Harris appears to be speaking to now. “This is a real erosion of Trump’s support within the party,” Snyder said. According to a recent New York Just/Siena Poll: Harris wins 9% of Republican voters; Snyder says he believes if she breaks 10%, it would win her the Electoral College.

To reach these voters, Harris also goes to Trump's hometown: Fox News. On Wednesday night, she did a 25-minute interview with Fox's Bret Baier in which she highlighted the number of Republicans who support her. “It is clear to me, and certainly to the Republicans who were on the stage with me,” she said, “that he is unfit to serve, that he is unstable, that he is dangerous and that people are exhausted.”

Harris again brought up Trump's use of the phrase “enemy within” to refer to his opponents. “This is a democracy, and in a democracy, the president of the United States, in the United States of America, should be willing to deal with criticism without saying he would lock people up,” she said.

The escalating confrontation with the wavering conservatives comes after several campaign phases with Trump's Republican critics. Former Rep. Liz Cheney endorsed Harris at an event earlier this month. Some former Trump officials have spoken out in support of Harris. A Harris-Walz ad uses the words of Trump's own vice president, defense secretary, national security adviser and chairman of the Joint Chiefs of Staff to argue that Trump is unfit to be president again.

Read more: The reintroduction of Kamala Harris.

Rob Gleason, who was chairman of the state Republican Party in Pennsylvania when Trump won in 2016, said Harris appears to be trying to boost her vote share in the suburbs to counter expected big losses in rural areas. “Ultimately, what is this election about: Do you like Trump or not?” Gleason says. “It’s not about Kamala Harris.”

On Thursday, Republican Voters Against Trump will launch a swing-state bus tour through Pennsylvania and Michigan to create a so-called “permission structure” for Republicans to break away from the former president. Each stop — in Philadelphia, Pittsburgh and Detroit — will feature former Trump voters who now support Harris. The group will also spend more than $4 million on a new advertising campaign in Pennsylvania, including 55 new billboards featuring former Trump supporters explaining why they can no longer support him. Republican Voters Against Trump is on track to spend a total of $32 million on ads featuring former Trump supporters.

Although it is almost certain that the vast majority of Republicans will support their candidate, in a razor-thin race even small defections can make the difference. “When things are as close as they are here,” says Gleason, “every vote counts.”

Correction added, October 18th: An earlier version of this story misstated the group that conducted a poll of Nikki Haley voters. It was Blueprint, not Haley Voters for Harris.