The 5th U.S. Circuit Court of Appeals has cleared the way for Texas Senate Bill 4, which bans so-called "sanctuary cities," to take effect.
The legislation had been held up after a federal judge in San Antonio blocked the law's enforcement in August while legal appeals played out.
SB-4 requires law enforcement to cooperate with federal immigration officials, also allowing local police and sheriff's departments to question the immigration status of anyone they arrest.
"We have heard from families that are changing the way they live. They are no longer going to the park, because they are concerned on the way there or there they could be asked for their proof of citizenship," said State Rep. Victoria Neave, D-Dallas.
Last year, Dallas declared itself a "welcoming community" for immigrants, establishing a new outreach program. On Wednesday, as SB-4 took effect, the city released the following statement:
"We do not anticipate the ruling affecting any procedures or law enforcement operations of the City."
The Dallas County Sheriff's Department declined NBC 5's request for an on-camera interview, citing pending litigation regarding immigration detainers. A spokesman for the sheriff's department did tell NBC 5:
"Our current procedures will not change, because they are in compliance with the terms of SB-4."
Some in Dallas, including former Republican candidate for sheriff, Chad Prda, believe the implementation of SB-4 is a step in the right direction.
"I think it's a door-opening day, to show that we have a firm stance on it and we will hold our law enforcement to the same standards we hold the community," Prda said.
Gov. Greg Abbott celebrated the decision on Twitter, calling it proof the law is not discriminatory.