The facts first: HERO is an anti-discrimination ordinance.
If it passes, Houston would join hundreds of cities nationwide that have such laws. The purpose is to provide a local remedy to fight discrimination based on race, sexual orientation or gender identity – among several other characteristics.
But ads calling for a no-vote on the ordinance tell a different story. Their message is the law will allow men (who pretend to identify as women) to enter women's bathrooms, because of its protection of transgender people.
Supporters stress HERO is about tolerance and non-discrimination. And the business community says it's important for Houston's economy.
But polling shows the message about men in women's bathrooms is resonating and it has put supporters on the defensive.
Now why is that?
"Everything that could have gone wrong and undermined public support of this ordinance happened," Bob Stein, a political scientist at Rice University, says. "And then some that you wouldn't have imagined."
He says Mayor Annise Parker has made a series of mistakes in her effort to implement the law.
First mistake: The ordinance's initial draft included language that specifically mentioned restrooms.
That part was later taken out, but the law theoretically still outlaws blocking someone from using the bathroom of the gender they identify with.
It's what got opponents up in arms from the beginning.
Second mistake: During the council discussion on the ordinance last year, Parker said, "The debate is about me. The debate is about two gay men at this table. It is very intensely personal."
Since then, opponents have used that comment to argue that the ordinance is part of Parker's "gay agenda."
Third mistake: When opponents organized a petition drive to force a repeal referendum, the city invalidated thousands of signatures, which led to a yearlong legal battle.
"When the court challenge to put it on the ballot was brought up, it no longer became a question of equal rights," Stein says. "It became a question of, ‘Does the public have a voice in this?'"
Fourth mistake: Lawyers for the city subpoenaed, among other communication, the sermons of pastors who have been outspoken HERO critics. That got Fox News and Mike Huckabee involved.
In July, the Texas Supreme Court ruled opponents had enough valid signatures. And a few weeks later, it ordered the city to change the ballot language, giving opponents yet another victory – and talking point.
And Stein says opponents' message about men in women's bathrooms rings louder than supporters' message of tolerance and non-discrimination.
He says unless they focus on the economic argument for HERO, chances are it will be repealed.