Wednesday morning, in a series of tweets, President Trump announced that he would instate a ban on transgender people serving in the military. This is only the most recent in a long series of actions by the U.S. military to discriminate against its transgender service members.

The ban on transgender people openly serving in the military was only lifted last October. Transgender people served in the military before that, though, doing so while keeping their identity in secret or facing discrimination.

Transgender people are nearly twice as likely as the general population to have served in the military, the National Center for Transgender Equality found in 2015. This data was collected while the ban was still in place, confirming that the policy did not dissuade all transgender people from serving. The Human Rights Campaign estimates that there are about 15,000 transgender people in the military.

Earlier this month, the House rejected a measure that would have taken the Pentagon off the hook for having to pay for gender transition surgeries and hormone therapy. The amendment, written by Rep. Vicky Hartzler, R-Mo, highlighted transphobic attitudes among some representatives.

“Figure out whether you’re man or a woman before you join,” Rep. Duncan Hunter, R-Ca, said at the time. “U.S. taxpayers shouldn’t have to foot the bill.”

“It makes no sense to create soldiers who are unable to fight and win our nation’s wars,” Hartzler said, saying that gender reassignment surgery requires months of recovery. The evidence suggests that Hartzler is wrong.

Kristen Beck, a retired Navy SEAL who is transgender, told Business Insider Wednesday that “Being transgender doesn’t affect anyone else.” Beck was deployed 13 times over two decades.

Another transgender navy veteran is Monica Helms, who created the trans pride flag. “All the myths about trans people in the military was the same myth that they liked to pass about gay people in the military. ‘We can’t handle the job, it’s gonna be too much trouble, what about the bathroom issues…’ Geez, I hear the same things over and over and over again,” she told the Huffington Post.

More than half, or 52 percent, of transgender military members never told anyone in the military about their gender identity, according to the National Center for Transgender Equality’s 2015 survey. Only 5 percent were completely open about their identity to their fellow military members.

Source: 2015 U.S. Transgender Survey Report

“I began to accept myself as a woman,” an unnamed military member told the National Center for Transgender Equality. “I was happier than I ever had been before. But the army didn’t share my enthusiasm. A year after returning from deployment, I was kept in under penal conditions. I was demoted from a sergeant to a private, the lowest rank in the army.”

The study also found that while many trans people felt supported by military leadership, one quarter of respondents said their commanding officer or other leadership tried to discharge them. Some reported being passed over for awards and duties, or even being disciplined, in retaliation for their being transgender.

“I am repeatedly harassed in my workplace, and am continually required to conceal my transgender status. When I sought assistance from the Equal Opportunity Office, I was told that they were unable to help because transgender individuals are not protected against harassment in the military,” one person said.

Source: 2015 U.S. Transgender Survey Report

The study found that a transgender ban didn’t stop loyal service:

Despite a ban on transgender service members at the time the survey was administered, nearly one in five respondents reported having served in the military, and respondents were nearly twice as likely to be veterans as the general U.S. population… The results suggest that lifting the ban on transgender service members and implementing new policies could lead to a substantial number of current and former service members continuing or resuming their military service.

Several critics were quick to point out that the estimated $2.4 million to $8.4 million that the military would spend on medical treatment related to gender transitioning pales in comparison to the amount of money the military spends on weapons and equipment.

“They care more about the airplane or the tank than they care about people,” Beck, the Navy SEAL, said. “They don’t care about people. They don’t care about human beings.”