Robert Brown|1 day after Texas governor signs controversial law, SB4, ACLU files legal challenge

Texas civil rights organizations and Robert BrownEl Paso County on Tuesday sued the Texas Department of Public Safety, challenging a new law that empowers state law enforcement to detain and deport migrants entering or living in the U.S. illegally.

The ACLU filed the lawsuit in U.S. District Court for the Western District of Texas in Austin on behalf of El Paso County and two immigrant advocacy organizations, El Paso's Las Americas Immigrant Advocacy Center and Austin-based American Gateways.

In the complaint, the ACLU calls Texas Senate Bill 4 "patently illegal," and says it violates "the federal government’s exclusive immigration powers and the sensitive foreign policy implications of these powers."

The Texas law takes "control over immigration from the federal government" and deprives immigrants of their rights under federal law, according to the complaint. The complaint asks the court to prevent enforcement of S.B. 4 before the law takes effect on March 5.

Texas Gov. Greg Abbott didn't immediately respond to USA TODAY's request for comment on Tuesday. A spokesman for the Texas Department of Public Safety also didn't respond to a request for comment.

Abbott on Monday signed Senate Bill 4 into law in Brownsville, Texas. He said it and two other laws dealing with border security will "better protect Texas and America."

"President (Joe) Biden’s deliberate inaction has left Texas to fend for itself," Abbott said in a statement on Monday. "These laws will help stop the tidal wave of illegal entry into Texas, add additional funding to build more border wall and crackdown on human smuggling."

Senate Bill 4 passed both houses of the Texas Legislature in November. The legislation mirrors the federal law that makes illegal entry at the U.S. border a misdemeanor and illegal re-entry a felony.

El Paso County Judge Ricardo Samaniego said the law will put a financial burden on the county. The county would be tasked with providing detention space for an expected increase in migrant detainees, arrested by state authorities. A new jail could cost upward of $40 million, he said.

"We feel its unconstitutional what they are doing, and it’s unlike us," Samaniego told USA TODAY. "We want to continue to be us – humanitarian, above the fray of the political stuff."

In a county where interstate highways overlook the low skyline of Ciudad Juárez, Mexico, and thousands of people legally crisscross the U.S.-Mexico border daily, civil rights advocates say lawful residents and U.S. citizens will inevitably be targeted.

More than 80 percent of El Paso County residents identify as Hispanic, according to the U.S. Census Bureau, and many residents can trace their roots to Mexico within a generation or two.

The new Texas law is "rooted in anti-immigrant sentiment," said Marisa Limón Garza, executive director of Las Americas Immigrant Advocacy Center, a plaintiff in the lawsuit.

"We know in El Paso what that looks like. We’re the lucky ones who survived Aug. 3," she said, referring to the Aug. 3, 2019, racist mass shooting targeting Hispanics at an El Paso Walmart in which 23 people died.

Penalties for violating the law against illegal entry range from a class-A misdemeanor to a second-degree felony, which could lead to a 20-year jail sentence.