MALVERN, Pa. — Vice President Kamala Harris joined forces with former Republican congresswoman Liz Cheney here Monday to denounce GOP nominee Donald Trump as unfit for office, part of the Harris campaign’s last-ditch effort to win over moderate Republicans and independent voters.

The unlikely pair was scheduled to appear later in Michigan and Wisconsin, holding onstage conversations in an effort to persuade undecided voters, especially Republicans with misgivings about Trump, to cast their ballot for Harris. With the occasional feel of a buddy movie, the two women — in similar pantsuits, Harris in green and Cheney in blue — assailed Trump as Harris heaped praise on Cheney for her support.

“I know that the most conservative of all conservative principles is being faithful to the Constitution,” Cheney said. “And you have to choose in this race between someone who has been faithful to the Constitution — who will be faithful — and Donald Trump.”

Cheney, a staunch conservative who served as the third-ranking House Republican until 2021, called endorsing Harris “not at all a difficult choice.” She warned about the risk posed by Trump’s relationships with dictators, saying that she has seen “how quickly democracies can unravel.”

Cheney, the daughter of former vice president Dick Cheney, emerged as one of the most vocal GOP critics of Trump after the Jan. 6, 2021, assault on the U.S. Capitol, and later went on to lose her seat in a Republican primary because of that criticism. She endorsed Harris in September and appeared at her first campaign event with the vice president this month in Wisconsin.

Cheney and her father are perhaps the most prominent Republicans to endorse Harris, the result of an intensive effort by the Harris campaign to recruit high-profile conservatives to back the Democratic nominee. Given the closeness of the election across all the battleground states, Harris’s advisers believe that attracting even a sliver of disaffected Republicans could prove to be pivotal.

On Monday, Susan Ford Bales, the daughter of former president Gerald Ford, announced that she was endorsing Harris.

At the Pennsylvania event, Cheney frequently noted that she has vast disagreements with Harris on a range of policy issues. But she said that Harris, unlike Trump, “will always do what she believes is right for this country.”

She also criticized Trump’s character more broadly.

“We’re going to reject the kind of vile vitriol that we’ve seen from Donald Trump,” Cheney said. “We’re going to reject the misogyny that we’ve seen from Donald Trump. … We have the chance to remind people that we are a good country. We are good and honorable people.”

In advance of Monday’s events, Trump posted on Truth Social to deride Cheney as a “war hawk.” The former president has been seeking to appeal to Arab American voters in Michigan.

“Arab Voters are very upset that Comrade Kamala Harris, the Worst Vice President in the History of the United States and a Low IQ individual, is campaigning with ‘dumb as a rock’ War Hawk, Liz Cheney, who, like her father, the man that pushed [President George W.] Bush to ridiculously go to War in the Middle East, also wants to go to War with every Muslim Country known to mankind,” Trump wrote.

Harris is pushing hard to broaden her appeal to centrist and Republican-leaning voters. She has distanced herself from some of the liberal policy positions she took in the 2020 Democratic primary, and on Monday she reiterated her promise to appoint a Republican to her cabinet if she wins.

“We need a healthy two-party system,” Harris said. “We need to be able to have these pretty intense debates about issues that are grounded in fact.”

“Imagine!” Cheney, seated next to Harris, chimed in.

As the crowd cheered, Harris said, “Wow, can you believe that’s an applause line?”

Chris Kofinis, a Democratic strategist and former chief of staff to Sen. Joe Manchin III (I-W.Va.), questioned the strategy of deploying Cheney, arguing that it does little to address voters’ main concern, which is the economy.

“Not sure what turnout model they are looking at, but there is no Cheney bloc of voters that I am aware of that will win this election for Harris,” Kofinis said. ‘Even worse, the more events they do with her, the more they remind Democrats, progressives and voters in general that her father was Dick Cheney and the enduring damage he did to this nation.” Many progressives see Dick Cheney as an architect of the Iraq War, which they regard as an enormous foreign policy blunder.

Even as she faces an electorate yearning for change, Harris has shied away from identifying clear differences with President Joe Biden. When asked by the moderator to outline her agenda, Harris said: “Mine will not be a continuation of the Biden administration. I bring to it my own ideas, my own experiences.”

But she did not articulate specific differences.Rather, Harris went on to explain her vision for an “opportunity economy” and her plan to address the nation’s housing shortage. Last week, Harris told NBC News that it was not part of the American tradition for vice presidents to criticize the president they serve.

Rep. Chrissy Houlahan (D-Pennsylvania), who represents Chester Countyafter flipping the seat in 2018, said she had asked the Harris campaign for the vice president and Cheney to appear in this swing district.

“This is absolutely where the rubber meets the road, literally where the red meets the blue,” she said.

She added, “It’s pretty grave when somebody as serious as [Cheney] and her father are coming out with this really important message to the American people, to Republicans and independents specifically, that this is a very different election.”

Several people in the audience suggested that Harris was having at least modest success in attracting former GOP voters.Mary Jean Moroz, who said she was a registered Republican until the Jan. 6 attack, gushed about watching Harris and Cheney onstage together. She voted for Harris by mail last week.

“It was nice to hear two women from two different parties come together with great ideas,” said Moroz, 60. “It’s very reassuring to see someone from my former party be so supportive of a Democrat.”

Glenn Gerhard, a registered Republican who voted for the libertarian candidate in the last two presidential elections, said he mailed in his ballot for Harris last week, marking his first time voting for a Democratic presidential nominee.

“It’s my first time voting for Democrat, and I may never again,” he said. “Hopefully I will never again.”

Gerhard, a 63-year-old professor at Temple University, said Trump “was unacceptable for any kind of office.” He called the former president one of the “crudest, lewdest and disgusting individuals.”

“I want my party back,” Gerhard said. “We have to defeat Trump in as loud and dramatic way as possible and then start getting back to the roots of the party.”

Amy Wang contributed to this report.