They're conservative, they oppose Trump. But some are at odds over whether to vote for Kamala Harris.

In the last two U.S. presidential elections, a number of senior Republicans opposed to Donald Trump's candidacy indicated they would not be voting for the party's nominee.

They also indicated they would not be voting for the Democratic candidate. Instead, many decided to write in another candidate's name. For example, former Republican presidential candidate Mitt Romney said he wrote in his wife's name in 2016; George W. Bush said that in 2020, he wrote in former Secretary of State Condoleezza Rice.

However, in 2024, there appears to be a shift among some Republicans, who have announced they will be marking an X beside the name of Democratic candidate Vice-President Kamala Harris in the upcoming presidential election.

Rylee Boyd, spokesperson for Republican Voters Against Trump told CBC News that there are certainly more Republicans coming out to support Harris than came out for Biden in 2020.

"I just think, at this point, everyone knows how much of a threat Donald Trump is," she said, adding that many of these Republicans are coming to terms with the fact that there isn't a place for them in the current Republican Party.

"And if there was ever going to be some type of normal Republican Party in the future, Donald Trump needs to be defeated for that to even be possible."

But for some anti-Trump conservatives, endorsing Harris is a bridge too far.

"I don't think it's good, frankly, for these Republicans who have been coming out and affirmatively endorsing a candidate who has no record of … any affinity for their governing program, their values and their ideology," Noah Rothman, a senior writer at the conservative website National Review and a frequent critic of Trump, told CBC News in a phone interview.

Still, while they may oppose many of her policies, those who have said they will vote for Harris see Trump, who continues to deny the 2020 election results, as a potential existential threat to democracy.

That's why some anti-Trump Republicans and former Republican staffers appeared on stage at the Democratic National Convention in Chicago to publicly announce their support for Harris.

Meanwhile, more than 200 staffers for four previous Republican presidential nominees have endorsed Harris, concerned that another Trump presidency would represent another four years of "chaotic leadership," jeopardize democratic movements abroad and hurt "real everyday people."

Although the Republicans and conservatives supporting Harris have not been as well known to the general public, that changed last week when former Republican Congresswoman Liz Cheney announced at Duke University that she would be voting for Harris.

Cheney, who co-chaired the House investigation into the Jan. 6, 2021, attack, and has been a vocal critic of Trump, said those conservatives and Republicans who oppose Trump don't have "the luxury of writing in candidates' names, particularly in swing states."

"As a conservative, as someone who believes in and cares about the constitution, I have thought deeply about this," said Cheney. "Because of the danger that Donald Trump poses, not only am I not voting for Donald Trump, but I will be voting for Kamala Harris."