The list of current and former members of Congress and other top Republican officials who are voting for Hillary Clinton in 2016 -- or at the very least, not voting for GOP presidential nominee Donald Trump -- just keeps growing. Who are they, really?
Here's your definitive guide to the prominent GOPers who are switching teams for the 2016 presidential election.
We'll update this list as the race continues.
Two former Republican EPA administrators
William D. Ruckelshaus served as EPA administrator under Nixon and Reagan. William K. Reilly was the former agency administrator under President George H. W. Bush,
Joint statement on environmental policy
They released a joint statement saying they couldn't support Trump because of his positions on environmental policy.
They said Republicans have a long history of protecting the environment, noting that it was Nixon who signed the bill creating the EPA in the first place.
Trump, on the other hand, denies the existence of climate change and wants to effectively dismantle the EPA, they said.
Rucklehaus was the EPA's first administrator. According to the EPA, Rucklehaus "concentrated on developing the new agency's organizational structure; enforcement actions against severely polluted cities and industrial polluters; setting health-based standards for air pollutants and standards for automobile emissions; requiring states to submit new air quality plans; and the banning of the general use of the pesticide DDT."
Reilly was one of the key figures who helped ensure the passage of the Clean Air Act, the key federal law intended to protect communities from the effects of air pollution.
Rep. Richard Hanna (R-N.Y.)
Hanna was the first GOP congressman to announce he was voting for Hillary Clinton.
A history of breaking with the GOP
Hanna has a long streak of breaking with his colleagues on key issues.
Though he's only been in Congress three years, Hanna has made waves within his party by supporting abortion rights, same-sex marriage, and the Equal Rights Amendment, a proposed Constitutional amendment to guarantee equal rights for women.
He is also the only Republican member of the Congressional LGBT Equality Caucus.
Former Sen. Larry Pressler (R-S.D.)
The former South Dakota senator endorsed Clinton after the deadly mass shooting at an Orlando gay nightclub earlier this summer, saying Clinton would be able to handle "explosive situations" better than Donald Trump.
Moderate 3rd party?
Pressler also has a history of breaking with his party on key issues, including gun control -- another reason he supported Clinton over Trump. Pressler has called for universal background checks on all gun sales and a ban on assault weapons.
Ultimately, Pressler has said he doesn't fully identify with the current GOP, and would like to create a viable, more moderate third party.
50 top GOP security officials
On Monday, 50 Republican national security officials signed a letter calling Trump a national security risk and pledging not to vote for him. (Here's the full letter.)
John Bellinger, who drafted the letter, said "some" of the 50 would vote for Clinton.
One notable signatory was Michael Hayden, the former director of both the CIA and National Security Agency. Though he's described himself as an "unrelenting libertarian," he was also a staunch proponent of increasing domestic surveillance during his time at the CIA. Hayden has worked under both Republican and Democratic administrations.
Former Michigan Governor William Milliken
In a statement, Milliken said he would endorse Clinton because he felt Trump did not display three important qualities: "tolerance, civility, and equality."
Longest-serving Michigan governor
Like many of the other Republicans backing Clinton, Milliken has long been viewed as a moderate, and has broken with his party multiple times to endorse Democratic candidates for office. In the 2004 presidential race, for example, he endorsed John Kerry over George W. Bush.
Milliken is the longest-serving governor in Michigan's history, and during his time in office, established a record of environmental conservation.
Former George W. Bush aide Lezlee Westine
Announcing her endorsement, Westine didn't say why she wouldn't support Trump. Instead, she only said Clinton had "the expertise and commitment to American values to grow the economy, create jobs and protect America at home and abroad."
This is not the first time Westine has professed support for women in government. During her time in the Bush administration, Westine worked to bolster Bush's standing among women by organizing a number of outreach events for women.
Westine also helped create a newsletter that featured stories about what the administration was doing for women.
Former Sen. Gordon Humphrey (R-N.H.)
More than anything, Humphrey's vote in November is anti-Trump. In a statement, he called the Republican nominee a "sociopath," and said he would "only vote for Hillary in the event of a very close contest."
A Kasich supporter
Humphrey, a two-term senator, was previously a John Kasich supporter. He was a strong supporter of "Delegates Unbound," the failed effort to let delegates pledged to vote Trump change their minds.
It might not be entirely clear that Hillary Clinton deserves to win the presidency, but it is thunderingly clear that Donald Trump deserves to lose.
Lavin served as Ronald Reagan's White House political director from 1987 to 1989. He called Trump "the emperor with no clothes" and said, "It is thunderingly clear that Donald Trump deserves to lose."
He also worked in the Commerce Department under President George H.W. Bush.