After the former South Carolina governor Nikki Haley dropped out of the Republican primary earlier this year, some conservatives across the US continued to vote for her in subsequent primaries, casting ballots that indicated dissent within a party that has otherwise fully embraced Donald Trump.

When Haley finally announced that she would be supporting the ex-president in the upcoming election, she said that it was on him to mobilize her loyalists.

“Trump would be smart to reach out to the millions of people who voted for me and continue to support me, and not assume that they’re just gonna be with him,” Haley said.

But it was the Biden campaign, not Trump’s, that actively began engaging Haley voters. “I want to be clear: There is a place for you in my campaign,” Joe Biden wrote on Twitter/X alongside an ad targeting Haley voters.

With the president out of the race now, some of those former Haley voters have organized behind Democratic candidate Kamala Harris in a political action group called Haley Voters for Harris.

Craig Snyder, the campaign director for the Haley Voters for Harris Pac, told the Guardian that the impetus for the group came after seeing how other Haley supporters continued to support her even after she was no longer a candidate.

“When we cast our votes in the primaries we weren’t really voting for her as an active candidate,” he said. “But we wanted to send a message that this was not the kind of Republican party that we wanted, that Trump’s period as the spirit-bearer of the party needed to come to an end.”

Snyder wondered what would become of Haley voters in the general election, and homed in on those who have made the decision, however reluctantly, to support Harris.

“For those of us in this group, our feeling has been that while we may disagree with the Democratic party on certain policy issues, the better choice is to continue our opposition to Trump by voting Democratic,” he said. “When President Biden made the decision to withdraw, we made the decision to continue along those lines and to support Vice-President Harris.”

John “Jack” Merritt, a self-described “center-right” and “strict constitutional constructionist”, registered to vote as a Republican in 1972. He said that, as a “political junkie”, he subscribes to various-leaning political newspapers and watches all of the major news networks. Though he supported Haley in the primaries and has served as a committeeperson for the Republican party in Bucks county, Pennsylvania, Merritt has decided to vote for Harris in November.

“I became incredibly disenchanted with the polarization of the two parties in the US,” Merritt said. “I picked the side that had the least amount of issues. I think [Harris and Walz] are more likely to ask for everything they want, but accept what they can get, especially if Congress turns out to be Republican this year. I’m looking for people who can truly govern, not just people who have ideological standards.”

Former Haley voters, many of whom are in swing states, will be vital in determining the outcome of the election, according to Snyder. As a result, Haley Voters for Harris is primarily targeting center-right voters by engaging in direct communication and education on political issues.

“We are developing the strongest arguments and factual accounts to give to voters to help them cross that last line,” Snyder, a registered Republican, said. “They’ve already taken their journey away from their Republican leaning. The question is: do they go the last mile and vote for the Democratic nominee? We want to get them across that last mile.”

But Snyder understands the difficulty that lifelong Republicans might face in trying to stomach support for a Democrat. Still, he said: “There may be disagreements between these voters and a Harris-Walz administration on matters of policy, but they are not fundamental moral values disagreements.”

In fact, some aspects of Harris’s history that may have dampened her appeal to progressives, such as her prosecutorial record, could work in her favor with Republicans.

“Her greatest weakness to a lot of people turns out to be kind of a strength for winning over Republicans. [She’s] now been kind of leaning into the law and order persona. But I think it’s smart politics that she’s doing that,” said Emily Matthews, a ​co-chair of Haley Voters Working Group, a coalition of Haley supporters and volunteers.

After Harris picked Walz as her running mate, Matthews said there was a lot of disappointment in the group, as they had favored Shapiro. But they’ve been focusing on Harris’s recent messaging as a bright spot.

“The border is just really important to a lot of kind of more moderate Republicans and, well, Republicans in general,” she said. “We’ve seen a change in tone from Harris and that has been very welcomed.”

Matthews is hoping Harris and Walz use this week’s Democratic national convention to share tangible policy shifts to the center, and to continue reaching out to disaffected Republicans and moderate voters. She said it’s important for the messaging to be clear about the Democrats’ more moderate and center successes.

Synder agreed. “When our voters hear those kinds of facts – there’s been more oil production under the Biden-Harris administration than under the Trump administration, the Biden-Harris administration pushed forward a bill to increase the number of border agents far greater than what Trump ever proposed – that is the way to have people get over this obstacle,” he said. “There’s a whole variety of just plain facts about a more moderate kind of approach that Harris has shown compared to this crazy leftwinger that she’s going to be depicted as by the Republicans.”

Last month, Haley’s lawyers sent a cease and desist letter to Haley Voters for Harris, urging the Pac to refrain from implying Haley’s “support for the election of Kamala Harris as President of the United States”.

But the letter hasn’t deterred Snyder. “Our organization has formally responded through our attorneys, and as of yet nothing further has happened,” he said. “We are continuing our work. At no time have we misrepresented Governor Haley’s position on the race, which is well-known to be support for former President Trump. We are merely calling our group what we are: Haley voters who have decided to vote for Vice-President Harris.”