Cheney's support is a test of how many Republican votes Harris can get

Prominent Republican backers of Vice President Kamala Harris are testing how many disgruntled GOP voters can be won over in her race against polarizing former President Donald Trump.

Former Wyoming Rep. Liz Cheney, a member of the Republican elite before Trump, became the latest and most prominent Republican to endorse Harris on Wednesday. Harris is also being endorsed by former Rep. Adam Kinzinger (R-Illinois) and hundreds of local Republican officials in an effort to expose what her campaign sees as Trump's soft underbelly to Republican voters uncomfortable with the former president's brash and unorthodox policies.

The campaign's consistent outreach is only part of Harris's path to Election Day. But now that there are no bigger names left on the ballot, the vice president will likely find out if she can get more support from disaffected Republicans – or if she's already reached her limit.

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“The Kinzinger/Cheney endorsement is designed by Democrats to make Republican voters who feel alienated by Trump's dishonesty, bad character, felony conviction, ignorance of public policy, etc., feel better about not just abstaining but actively expressing their displeasure by voting for Harris,” said former Rep. Mo Brooks (R-Ala.), a six-term conservative lawmaker who clashed with Trump in his 2022 Senate campaign.

“The number of Republican voters who will be swayed by Republicans supporting Harris is relatively small,” he added. “But in an otherwise close race, it could be the difference between victory and defeat.”

MORE: Former Republican Vice President Dick Cheney will vote for Harris, says Liz Cheney

Cheney, a rising star of Republicans of the past who became both an outsider and the face of the anti-Trump Republican side after the Jan. 6 insurrection, said Wednesday in Republican-leaning North Carolina that she would support Harris out of fear for American democracy. On Friday, she said her father, former Vice President Dick Cheney, would do the same.

“I felt like it was a particularly important discussion that we had for the first time in North Carolina, where, you know, one of the questions that I hear from Republicans who know they wouldn't support Donald Trump again but, you know, kind of said, well, maybe I'll just write somebody up,” she said Friday. “And I think that we don't have that luxury, particularly when we're talking about states where we know it's going to be close, where the election is going to be decided, and I think it's really important to recognize the nature of the election that we have,” she said.

The support is just part of Harris' strategy to win over undecided Republican voters.

The party sees the renegade Republicans as an opportunity for expansion, especially after hundreds of thousands of voters abandoned Trump in the Republican primary and voted for former South Carolina Gov. Nikki Haley, even after she ended her campaign. And Trump has shown little interest in his opponents. At a town hall meeting on Thursday, he said, “I don't want that person,” when asked about people who didn't vote for him in the primary.

The Democratic National Convention last month featured numerous Republican speakers, including Kinzinger. Harris has said she would appoint a Republican to her Cabinet. A network of local officials and former Trump administration staffers have lined up to campaign for Harris. And the campaign has spent millions of dollars on advertising to suggest to Republicans that they have a place in the modern Democratic Party.

To be sure, Harris is not putting Republicans at the center of her strategy, aware of the limited chances of challenging a Republican Party largely under Trump's thrall. But Democrats insist that winning over a small portion of protest voters can pay off – and that big names like Cheney and Kinzinger could provide some Republicans with the foundation to vote Democrat in November.

“We know there are a number of Republicans who are in a similar situation. They are not necessarily Trump supporters. Some may be, but they may not yet know what they think of Vice President Harris,” said Democratic strategist Karen Finney. “This kind of support sends a signal to those voters that there is someone else who is prominent but feels the same way about Trump and has similar concerns, and who they respect.”

It is still unclear to what extent Cheney will work to convert Republicans, but there is already a playbook for how she can exert her influence.

In 2022, she invested $500,000 in an Arizona ad in which she sharply attacked Kari Lake and Mark Finchem, the Republican candidates for governor and secretary of state and vocal anti-voters, saying, “I don't know if I've ever voted for a Democrat, but if I lived in Arizona, I absolutely would.”

Both Lake and Finchem lost their races.

But national elections in a midterm year are not the same as a historic presidential election with a Republican candidate soaking up an unprecedented amount of political oxygen.

Polls have shown Harris' approval ratings among Republicans in the single digits, and Trump has been a public figure for years – nearly a decade since he first launched his campaign – so perceptions of him are solid enough to withstand the new outpouring of support.

“My instinct tells me that this [Republicans] And [independents] are not impressed by this – they are already on board with Harris,” said Chuck Coughlin, an Arizona strategist who left the Republicans in the Trump era.

“Anyone who is already voting against Trump because they hate Trump is already there,” agreed Republican pollster Robert Blizzard. “They're not going against him because some former congressman says they're going to.”

Other Republicans said voters might not be convinced by Cheney and Kinzinger's dire warnings about the threat Trump posed to democracy, given that the guardrails held despite the Jan. 6 attack on the U.S. Capitol by a pro-Trump mob three years ago.

“I think Kinzinger and Cheney are not as convincing to undecided voters or 'Haley' voters. They don't usually buy into the apocalyptic narrative that they use, which is that democracy ends with Trump. I think the most convincing are those who worked with him, like [Jon] Kellys, [Mark] Esper, [Henry] McMaster, [John] Bolton, etc., who can say they worked with him and he is unfit,” said anti-Trump Republican strategist Rob Stutzman, referring to former Trump administration officials with backgrounds in national security.

And given all the work and money Harris has already invested in appealing to Republicans, some experts speculated that the ceiling of Republican support for the vice president may already have been reached.

“That certainly helps. But I'm not sure that her endorsements are leading indicators of the Never Trump movement, but rather lagging indicators of the movement,” said former Florida Rep. David Jolly, who left the Republican Party over disagreements with Trump. “The real catalyst for strengthening the coalition was Harris herself.”

Trump's campaign team, for its part, seemed unconcerned about Cheney's recent recommendations.

When asked what the campaign team thought of Cheney's announcement that she and her father would vote for Harris, campaign spokesman Steven Cheung replied: “Who the hell is Liz Cheney?”

Isabella Murray of ABC News contributed to this report.

Cheney's support is a test of how many Republican votes Harris can get. Originally published on abcnews.go.com