The San Antonio Police Department Chief William McManus and LULAC leaders have all spoken out against S.B. 4, the law banning sanctuary cities in Texas.

Opponents took to the LULAC National Convention on Thursday to update the public on the status of a federal lawsuit.

Both sides spoke before Judge Orlando Garcia a couple of weeks ago inside the John H. Wood Federal Courthouse in downtown San Antonio.

Opponents of S.B. 4 are preparing additional arguments on why the law is unconstitutional and why the judge should issue an injunction. The state will also have until the July 20 to respond with their post-trial briefs.

The law is set to go into effect September 1, but the fight to stop it continued Thursday on the third floor of the Henry B. Gonzalez Convention Center.

"There's enough divisiveness in the country, and that's what S.B. 4 is doing," said Roger Rocha, president of LULAC National.

Rocha said that the "show me your papers law" will have an economic strain on taxpayers.

"Texas is ground zero for this type of law. If this passes in Texas, other states will follow," Rocha said. "So it has to be defeated here in Texas. If not, it will completely change our way of life."

LULAC was the first to file a lawsuit against S.B. 4, claiming the law is unconstitutional and pins a target on minorities.

"Make no mistake about this, S.B. 4 was specifically created to target Latinos," Rocha said. "We are the largest minority in Texas. Who do you think is gonna be pulled over?"

Opponents also stressed the negative effects on families, should they be separated by the new law. Currently, 2,000 Texas children are in foster care because their parents were deported. Across the country, there are close to 100,000.

Under S.B. 4, officials say that the number could double.

"Any attempt that suppresses and violates human rights and civil rights is worth fighting for," said Raul Reyes, mayor of the City of El Cenizo, a border town in South Texas that took the lead in the lawsuit against S.B. 4.

Other big cities like Austin and San Antonio joined in later.

The law says that police cannot profile in order to enforce S.B. 4, and any officials refusing to comply could be removed from office.

"That is laughable, because how else do you determine to ask someone for their papers other than their skin color or their accent. What else do you base it on? That, ladies and gentleman, is profiling in its pure form," Chief McManus said.

McManus added that, at the moment, SAPD spends zero time enforcing immigration matters.

Should they begin to do so come September 1, that could mean delays in responding to 9-1-1 calls.

"For every second an officer spends dealing with an immigration matter, that's a second that responding to your emergency calls is torn away. We don't have the capacity to deal with immigration enforcement,” Chief McManus explained. “We don't even have the authority to enforce immigration matters."

Judge Garcia could make a decision as early as August on whether or not to issue an injunction.

"We have to believe that we will prevail because it's the right thing to do," Rocha said.

Along with S.B. 4, this year's LULAC National Convention and Exposition will address other pressing issues in the Latino community, like the border wall, deportations, and the new administration’s cutbacks on education and health and human services.

For a list of events in the LULAC National convention happening through Saturday, click here.