Many of the social changes that have transformed the military under President Obama would be undone under a Trump administration, leaving some troops once again afraid to serve, according to one Navy vet.

Jim Lyons, who previously served in the Navy aboard two aircraft carriers, praised the courage of President Obama and Congress to repeal "Don't Ask, Don't Tell," the law that prevented gay troops from serving openly. But he said he feels much of that hard work will be undone if the GOP nominee wins the White House.

"I fear that the hard-fought gains that the U.S. and the U.S. military has made for the last several years will evaporate under a Donald Trump presidency. His bigoted and racist and divisive remarks are not taken lightly by those on the receiving end of them and it's giving a rise to a culture of hatred and permissiveness to be a thug," Lyons said. "If he is elected, certainly, gay U.S. service members will live in fear."

Lyons was part of a group of veterans that spoke on Capitol Hill on Thursday to call on GOP leaders, including Sen. John McCain, to revoke their endorsement of Trump because of his recent remarks about the military. They specifically cited Trump's conflict with a Gold Star family, his comments that the Russians should hack into Clinton's emails and reports that be questioned why the U.S. can't use its nuclear weapons.

Following the press conference, the veterans delivered the petition, which had collected more than 100,000 signatures, to McCain's office.

The veterans said that they were asking lawmakers to uphold the same oath they took when they joined the military: to protect the country against all enemies foreign and domestic, a class they feel includes Trump.

"We need to remind Donald Trump that we are people, not pawns," said Crystal Cravens, a former Army sergeant.

Trump recently announced that he wouldn't endorse McCain because the Arizona Republican could have worked harder for vets. Alexander McCoy, a former Marine, said that whether McCain listens to the petition will show whether or not he supports veterans.

"He has represented his state with all the patriotism and we would expect from someone of his record. We hope that he listens to us today and believe that will be a large indication of whether he stands with veterans or not," he said.

Asked if they supported Hillary Clinton as a commander in chief, the group stressed that their political views on that may differ, but they are united in their stance that Trump is a dangerous choice for the country.

During a slow month in Washington, where lawmakers are largely back in their home districts, media outnumbered the seven veteran speakers nearly three to one.