Editor's note: This story has been updated.

The question isn’t whether or not the Texas attorney general’s office will be hauled to court over a Texas Senate bill to ban “sanctuary” policies in Texas — but, more likely, when they’ll be asked to defend Senate Bill 4 in a federal court.

“There are ways to challenge the bill before September to prevent its implementation and we’ll be looking to challenge this as soon as possible,” said Marisa Bono, a staff attorney with the Mexican American Legal Defense and Educational Fund.

Bono was referring to the Sept. 1 date the bill is slated to take effect. Senators approved the controversial measure late Thursday after it cleared the Texas House last week.

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The legislation makes sheriffs, constables, police chiefs and other local leaders subject to a Class A misdemeanor and possible jail time if they don’t cooperate with federal authorities and honor requests from immigration agents to hold inmates who are subject to deportation. It includes civil penalties for entities that violate the provision that begin at $1,000 for a first offense and climb to as high as $25,500 for subsequent infractions. It also applies to public colleges.

The bill also includes a controversial House amendment that allows police officers to question a person’s immigration status during a detainment — not just during a lawful arrest. Democrats and immigrant rights groups argue this makes the bill "show-me-your-papers"-type legislation that will allow police to inquire about a person's immigration status during the most routine exchanges, including traffic stops.

Abbott and other supporters of the bill claim it’s about the rule of law and deterring people who are already in the country illegally from committing more crimes in cases where they're arrested but subsequently released because jails refuse to hold them longer than they have to.

“Banning sanctuary cities is about stopping officials who have sworn to enforce the law from helping people who commit terrible crimes evade immigration detainers,” said state Sen. Charles Perry, the bill’s author. “Senate Bill 4 protects all Texans though uniform application of the law without prejudice.”

But Democrats and other opponents of the bill are livid over the measure, and have a laser-focused rage over the House amendment.

Bono, whose firm represented some of the plaintiffs who successfully sued the state over its 2011 redistricting maps, said that litigation could focus on several issues, including what power states have to craft their own immigration-enforcement laws. A separate issue is whether the requests from federal authorities, known as detainers, are mandatory or voluntary.

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“There are a number of provisions throughout the bill, including the detainer provision and several other sections, that raise concerns about preemption and vagueness” in the bill, she said.

The bill was passed after a San Antonio-based three-judge panel ruled that lawmakers either violated the U.S. Constitution or the Voting Rights Act in 2011 by intentionally watering down the strength of minority voters in Texas. That was just weeks after a federal judge ruled that Texas lawmakers intentionally discriminated against Hispanic and black Texans after the Legislature passed a strict voter ID law in 2011.

Bono said although those rulings prove state Republicans have had minorities in their crosshairs for years, she was confident plaintiffs would prevail in a lawsuit against SB4 because of the bill itself.

“We consider the wind at our backs because of the way the bill is worded,” she said. “But certainly the state’s history of intentional discrimination — and specifically recent targeting against the immigrant community — will be helpful in the narrative.”

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