After the brutal death of Kathryn Steinle by an illegal immigrant, some Republicans are finally demanding the Obama administration crackdown on "sanctuary cities," but it looks like the White House can't do much.

Several Republican presidential candidates, including Sen. Marco Rubio (R-Fla.), former Govs. Rick Perry (R-Texas) and Jeb Bush (R-Fla.), are now becoming more hawkish on immigration and demanding new limits on sanctuary cities, reported the National Journal Monday.

"There are over 200 sanctuary cities and counties in this country, and the U.S. Department of Justice has done absolutely nothing—nothing!—to prevent this," Perry said last weekend.

But so far most of their cries for change have fallen on deaf ears. No major sanctuary city, including San Francisco Steinle was murdered, has agreed to comply with federal immigration officials.

Legal experts say it's unclear how much the federal government can force the cities to comply, mostly because the Justice Department has never tried. One proposal by Sen. Tom Cotton (R-Ark.) is considered the best option by for clamping down on sanctuary cities.

The senator's plan is to withhold Homeland Security grants from any city where the official policy prohibits the police force from working with ICE.

Texas A&M law professor Huyen Pham, who specializes in immigration law, said it was the most effective way to eliminate the cities with rogue immigration laws.

Despite Cotton's best efforts, it is not the first time Congress has tried to come down on sanctuary cities. Two laws passed in 1996 mandate that localities can't pass laws prohibiting local officials from sharing information with federal immigration officials, but the federal government has rarely tried to enforce that law.

Many areas have found their way around the law because they don't use local resources to determine residents' immigration status. This means that they don't technically refuse to share intelligence with ICE because they don't gather any immigration information in the first place.

"Though this method does not directly conflict with federal requirements that states and localities permit the free exchange of information regarding persons' immigration status, it results in specified agencies or officers lacking any information about persons' immigration status that they could share with federal authorities," said a 2009 Congressional Research Service report.

Cotton's new proposal has found support by a majority of Americans. A recent poll by Rasmussen Reports claimed that a majority of voters support cracking down on sanctuary cities. About 58 percent even supported withholding federal funds.

But only time will tell if another law on the books will stem this growing problem.