© AP Photo/Eric Gay Texas Gov. Greg Abbott delivers his State of the State address to a joint session of the House and Senate, Tuesday, Feb. 17, 2015, in Austin, Texas. Abbott told lawmakers that roads, education and border security are the biggest issues facing Texans.

The American Civil Liberties Union has put out a “travel alert” for anyone planning to visit Texas, just days after Texas Gov. Greg Abbott signed a so-called “sanctuary cities” ban into law.

The goal of the alert, officials say, is to warn travelers and residents about the ban, known as Senate Bill 4, that lets law enforcement officers ask people during regular stops whether they are in the country legally.

“The ACLU’s goal is to protect all Texans and all people traveling through Texas — regardless of their immigration status — from illegal harassment by law enforcement,” Lorella Praeli, ACLU’s director of immigration policy and campaigns, said of the alert issued about Texas in more than a dozen states.

“Texas is a state with deep Mexican roots and home to immigrants from all walks of life,” she said. “Many of us fit the racial profile that the police in Texas will use to enforce Trump’s draconian deportation force.”

The new law goes into effect Sept. 1.

Critics have blasted the controversial Texas law, likened to Arizona’s “papers, please” law passed in 2010, which has drawn repeated protests at the Capitol. They say they fear Hispanics will be targets of racial profiling and worry it will bring a “chilling effect” to immigrant communities across the state.

The Texas measure — which follows a move by President Donald Trump’s administration to withhold funds from areas that don’t comply with immigration laws that could lead to deportation — also threatens law enforcers with jail time if they don’t work with federal immigration agents.

Elected officials and law enforcement agencies don’t get to pick and choose which laws they will obey.

“Elected officials and law enforcement agencies don’t get to pick and choose which laws they will obey,” Abbott said about the law. “Citizens expect law enforcement officers to enforce the law, and citizens deserve for law breakers to face legal consequences.”

Abbott on Sunday, when the Legislature was not meeting and without advance notice, signed the bill into law and broadcast the signing on Facebook.

“Let’s be clear about something,” he said during the broadcast. “We all support legal immigration. It helped to build America and taxes. Texas strongly supports the legal immigration that has been part of our state since the very beginning.

“But legal immigration is different from harboring people who have committed dangerous crimes.”

This was a significant departure from the way Texas governors traditionally handle bill signings, particularly of items that were among their legislative priorities.

Generally, the governor holds a press conference with authors of the bill to sign such a bill. But an Abbott spokesman said the governor went onto social media to sign this bill because that’s “where most people are getting their news nowadays.”

ACLU and others promise to fight this measure.

“We plan to fight this racist and wrongheaded law in the courts and in the streets,” said Terri Burke, executive director of the ACLU of Texas. “Until we defeat it, everyone traveling in or to Texas needs to be aware of what’s in store for them.

“The Lone Star State will become a ‘show me your papers’ state, where every interaction with law enforcement can become a citizenship interrogation and potentially an illegal arrest.”

The so-called sanctuary movement has been around for decades and repeated attempts to create a ban died in Texas session after session, until this year. The term often refers to communities where policies prevent law enforcers from helping enforce federal immigration rules.

Despite opposition to this measure by police officers across the state, Republicans maintain that this measure is needed.

Abbott’s office stressed that the measure includes penalties of up to $25,500 for each day of a violation, removal from office for officials who don’t enforce the law and a Class A misdemeanor for top law enforcers who don’t enforce federal immigration detainer requests.