During Governor Greg Abbott's State of the State address Tuesday, he took aim at sanctuary cities.

"Senator Perry, this is the session when we will ban sanctuary cities Texas," Abbott said as the crowd applauded. 'And I'm declaring this an emergency item so you can get to work on it tomorrow."

The very next day, Senator Charles Perry (R-Lubbock) and members of the Senate Republican Caucus came together to voice their support for Senate Bill 4.

"The integrity of our civil and criminal justice system is built on the premise it applies to everyone equally. When you undermine that by having individuals decide which laws they will apply, when they will apply them and how they will apply them you begin to create a perception of a double standard," said Perry.

The bill will require all law enforcement entities in Texas to comply with U.S. Immigration and Customs Enforcement (ICE) detainers, which are voluntary requests to hold an arrested person in custody while ICE investigates their immigration status.

Many have coined it a crack down on "sanctuary cities", a vague term SB4 now somewhat defines.

"When they have policy, implied or implicit, formal or informal, or, if you will, just kind of soft throughout their system that says you cannot enforce the ICE detainers or you cannot enforce the inquiry provisions that have been held constitutional, you can't enforce these laws, then you have a sanctuary city," said Perry.

Senator Dawn Buckingham (R-Lakeway), who lives in Travis County which is often referred to as a "sanctuary city", backs the bill.

"We have a clear message to our law enforcement officers, obey the rule of law, respect the detainers or else there are dire consequences," said Buckingham.

Those consequences are the loss of state grants. The bill does exempt witnesses and victims of crime from being held on ICE detainers and hospitals also don't have to comply.

But there is much opposition to the bill. The Mexican American Legislative Caucus held a news conference last week speaking out against the bill and 14 others similar to it that target sanctuary cities.

"Call it sanctuary cities but I call it what it is, this is an opening door to racial profiling," said Senator Sylvia Garcia (D-Houston).

The Texas Advocates for Justice held a march from the federal courthouse to the Capitol Wednesday to rally against SB4 and a bill to preempt a city's fair chance hiring ordinances.

Perry and the senators reiterated they support legal immigration into the U.S. and Perry added he supports "good sanctuary cities" or cities that chose to provide services for immigrants while still carrying out ICE detainers.

The Senate State Affairs Committee has scheduled a hearing on SB4 for Thursday morning at 8:30 am.