By the time Nicolas Talbott, a second lieutenant in the U.S. Army reserve, checked on the incoming texts buzzing on his smart watch, he found dozens of messages waiting for him. Talbott, a transgender man who took his oath of enlistment in March, instantly knew what the messages were about: President Donald Trump was about to sign his much-anticipated executive order placing restrictions on transgender members of the U.S. armed forces.

"Well, it happened," Talbott, 31, said in an interview. "Here we go." And transgender service members in the military were ready. Within 15 hours of that executive order, Talbott joined five other transgender service members in a lawsuit filed on Tuesday by GLAD Law, a LGBTQ+ rights advocacy group, and the National Center For Lesbian Rights (NCLR). The lawsuit alleges that the new restrictions are violating constitutional guarantees of equal protection.

The long-term aim is not just to block Trump's executive order, but to enshrine permanent protections for transgender troops, Talbott said.