CARSON CITY, Nev. >> Civil rights lawyers pleaded with Nevada’s Supreme Court today to uphold a state court ruling that would keep off the ballot in November what they describe as an “anti-immigrant” measure crafted by the Republican state Senate leader banning so-called sanctuary cities.

Lawyers for a political action committee formed by Sen. Michael Roberson of Las Vegas — who’s now running for lieutenant governor — urged the justices to strike down the earlier ruling and let the petition initiative move forward so Nevada voters can decide for themselves.

The measure would amend Nevada’s Constitution to prohibit the state, counties or local governments from passing any law or ordinance that prohibits, limits or discourages cooperation in the enforcement of U.S immigration laws.

Carson City District Judge Todd Russell ruled in January that the proposal is excessively broad and could have wide-ranging impacts on numerous laws in violation of Nevada’s ballot initiative rules mandating they address only one subject.

Lawyers for the American Civil Liberties Union said it’s intended to confuse and mislead voters into supporting sweeping changes under the guise of targeting sanctuary cities, which currently don’t exist in Nevada.

“Nevada’s immigrant families are at risk under this mass deportation agenda,” said Theresa Navarro, one of the plaintiffs who filed suit to block the measure.

ACLU lawyer Amy Rose of Las Vegas said at a news conference before today’s oral arguments that the “anti-immigrant measure … will tear families apart.”

Marc Elias, a lawyer based in Washington D.C. who argued the case today for the ACLU, said the “single-subject requirement” regulating ballot measures and another mandating that the potential impacts of the measure be identified are intended to “prevent voter confusion and promote informed decisions.

“It is simply an error to state that federal immigration law is a single subject,” he said, offering a list of potential impacts on everything from Social Security, schools and medical care, to rights to legal counsel and even U.S. treaties.

“It is an umbrella of a multitude of subjects … a body of ever-changing federal laws involving tens of thousands of pages of administrative regulations and hundreds of court decisions,” he said. “It covers virtually everything the federal government does.”

Paul Georgeson, a Reno lawyer representing the political action committee Prevent Sanctuary Cities, said that while U.S. immigration laws “are a broad subject, nothing prohibits Nevadans from exercising their rights to amend their constitution.”

“You can have broad subjects so long as they are a single subject,” he said.

Georgeson said the potential impacts argued by the ACLU are “speculative” and “hypothetical.” And while Nevada doesn’t currently have any sanctuary cities, he said other states such as California “have failed to cooperate in enforcement of U.S. immigration laws.”

If allowed to move forward, Roberson’s PAC would have until June 19 to collect the necessary signatures to get the measure on the ballot. He said in a statement issued today by his campaign for lieutenant governor that the proposal is “under attack from national liberal interest groups.”

“By now you’ve heard of states like California adopting reckless Sanctuary City policies that risk putting dangerous criminals back on the streets,” Roberson said.