SAN ANTONIO, Texas - Nearly 200 Houstonians joined hundreds more from across Texas in San Antonio on Monday to protest the state’s controversial sanctuary city law as a hearing on a lawsuit challenging it began.

The rally was held outside the federal courthouse where a judge was hearing arguments for and against Senate Bill 4 in order to decide whether to block the bill from taking effect in September.

The law, signed by Governor Greg Abbott in May, lets police officers ask the immigration status of people they detain and punishes officials who don’t cooperate.

On June 21, Houston City Council voted 10-6 to join major cities like San Antonio, Austin, and Dallas in a lawsuit against SB 4.

Mayor Sylvester Turner and Police Chief Art Acevedo worry it will create distrust in the Hispanic community, leading to fewer crime victims and witnesses coming forward and a less safe city for everyone.

Legal staff from the City of Houston testified against the bill, as did Rep. Ana Hernadez (D-Channelview), who was once undocumented herself.

While the courtroom filled up early on Monday, those who couldn’t watch rallied outside, including Abraham Espinosa, who was one of 100 or so people who traveled by bus from Houston with immigrant rights group FIEL Houston.

“They know that we are there and that we’re opposed,” said Espinosa, when asked what impact he thought the rally could have. “Is it gonna make a difference as far as a decision inside of the hearings? I’m not sure in the sense that, obviously, they have power, but as far as the people are concerned, we are opposed to SB 4.”

No cameras or recording devices were allowed in the courtroom.

According to tweets from journalists and activists inside, the judge told the courtroom he’ll review the evidence but isn’t sure when he’ll make a ruling.