Bathroom bully bills — legislation that bars transgender individuals from using restrooms that match their gender identities — will form the next front line in the push for equal rights, according to transgender advocates who are readying themselves for the fight ahead.

“We are going to battle over bathrooms,” said Mara Keisling, executive director of the Washington-based National Center for Transgender Equality, on Friday.

While spreading awareness about violence against trans people as well as ending employment and housing discrimination will remain critical issues, Keisling said she anticipates that going forward, the struggle over the bathroom laws will be central.

Lawmakers in several U.S. states — including Florida, Kentucky, Minnesota and Nevada — have introduced bills in the last year that would prevent trans students from using the facilities corresponding to their gender identities while at school.

Meanwhile legislators in other states such as Texas proposed laws that would require adults and children to use the bathroom and locker room corresponding to their sex assigned at birth.

None of the laws have passed. “We beat them all,” Keisling said, “this time.”

School districts attempting to create such policies, she said, are violating Title IX of the Civil Rights Act, which protects public school students from gender discrimination.

The attempts, however, set up a “pernicious” precedent, according to Keisling, and conservatives will likely keep pushing variations of these laws.

“The right wing, pretty much all they have left are the bathrooms,” she said.

A decade ago, bathrooms were a taboo topic among the trans advocacy community, Keisling said: “We were terrified to talk about it, because it was a losing battle.”

Given increased media visibility and public understanding of what it means to be transgender, she says the conservative right has drummed up bathrooms as an issue for raising support.

Former Arkansas Gov. and Republican presidential candidate Mike Huckabee said in June that supporting transgender rights would allow men to lie about their gender identities in order to spy on women in restrooms.

Texas state Rep. Debbie Riddle, a Republican, wrote in a Facebook post in January that the state's proposed bill “will protect women & children from going into a ladies restroom & finding a man who feels like he is a woman that day.”

If any proposed bathroom bills do get signed into law, they are likely to face legal challenges. Gender identity and expression is included in Title IX of the 1972 Education Amendments Act, and the U.S. Justice Department filed a statement of interest in a case from Virginia, writing that it was in the public's interest to make sure that “all students, including transgender students, have the opportunity to learn in an environment free of sex discrimination.”

At least two lawsuits have already successfully upheld access to bathrooms for trans children. In 2013, the family of Coy Mathis, a transgender first-grader, won a lawsuit against their Colorado school district that allowed her to use the girls’ bathroom. In 2014, Maine's highest court ruled in favor of transgender student Nicole Maines after she sued when her high school required her to use a separate staff restroom.

The only time Keisling, who is transgender, has ever been bothered about her own bathroom usage was when she was attending a dinner with a group of transgender lawyers at a restaurant in New York City.

As she prepared to enter the women’s bathroom, a waiter tried to stop her. “I know what you are,” Keisling recalled him saying to her.

Thinking of the crew of lawyers back at the table, and knowing her rights — New York City amended its human rights law in 2002 to protect against gender identity discrimination in housing, employment and public accommodation — she responded, “This is illegal,” and breezed right past him.