More than 100 cities and counties have passed laws prohibiting gender-identity discrimination, including Phoenix, Atlanta, New Orleans and Dallas. Those laws are also not uniform. For example, Baltimore County in Maryland approved a measure in 2012 protecting transgender people from discrimination. It did not apply to "distinctly private or personal" facilities. Tennessee lawmakers tried going in the other direction with a proposal similar to Arizona's in 2012, but it failed to gain support.
Some state laws are being tested in court. In one case, a Colorado family filed a complaint with the state's civil rights office after their first-grader, who was born a boy, was prohibited from using the girl's bathroom at her elementary school.
In recent weeks, Massachusetts and California took steps to clarify their gender-identity discrimination bans and ensure equal access for transgender students at gender-segregated facilities.
In Arizona, where Republicans control state government, Kavanagh said government shouldn't allow people to use facilities based on "you are what you think you are." He said he was worried an anti-discrimination ban passed in Phoenix last month would serve as a cover for pedophiles who want to expose themselves to children of the opposite gender.
"This law simply restores the law of society: Men are men and women are women," he said. "For a handful of people to make everyone else uncomfortable just makes no sense."
Some fret anti-discriminatory laws force businesses to spend money on renovation projects in order to provide unisex facilities and avoid complaints from customers who don't want to share bathrooms and dressing rooms with transgender people. They say Arizona's proposed law would instead protect businesses from bogus complaints from people who aren't transgender.
"Someone can just say 'oh, I feel like I am a woman,'" said Aaron Baer, a spokesman for the Center for Arizona Policy, a powerful conservative group. "That person can just say, 'you are discriminating against me.'"
But Masen Davis, executive director for the Transgender Law Center in San Francisco, said Arizona's proposed ban would target people who look different, regardless if they are transgender or not.
"No one should have to live in a world where they have to show their papers to pee," Davis said.
Cristina Silva can be reached at http://www.twitter.com/cristymsilva.