Based on comments during oral arguments on Dec. 8, the U.S. Supreme Court appears divided on an immigration case that could have far-reaching ramifications for construction companies and other businesses.

The case, Chamber of Commerce v. Whiting, is important to construction firms. A Pew Hispanic Center study found that “unauthorized migrants” accounted for 14% of the construction workforce in 2005.

At issue in the case is whether an Arizona law imposing sanctions on companies that knowingly hire illegal immigrants is preempted by federal immigration law.

States that have similar laws in place or would like to enact such legislation are watching the case closely.

An unlikely coalition of immigrants’ rights advocates, unions and business groups challenged Arizona’s law. The groups contend the law should be preempted by the 1986 federal Immigration Reform and Control Act (IRCA). Employers particularly oppose a provision that some call the “death penalty,” revoking the licenses of firms that hire illegal immigrants.

It is difficult to predict how the justices will rule, based on questions they asked at oral arguments. But conservatives on the court, led by Justice Antonin Scalia, seemed sympathetic to Arizona’s view. Liberal justices challenged some of the state’s arguments.

A split 4-4 decision is possible, because Justice Elena Kagan, a former U.S. Solicitor General, recused herself from the case. A tie would leave the Arizona law in place. But the lack of a majority could prompt the court to take up another, similar immigration case to resolve the issues.

Carter G. Phillips, who represented the U.S. Chamber of Commerce, told the court Congress carefully drafted IRCA to combat the hiring of illegal immigrants and prevent discrimination. Arizona’s law, he said, upends that balance.

Arizona Solicitor General Mary R. O’Grady said the state’s law is a licensing statute and falls within IRCA’s provision that preserves licensing authority for states.