The Supreme Court on Wednesday appeared closely divided over whether immigrants detained for more than six months by the U.S. government while deportation proceedings take place are eligible for a hearing in which they can seek their release.

The case takes on additional importance with the expectation that President-elect Donald Trump will ramp up immigration enforcement when he takes office on Jan. 20, as he pledged to do during his election campaign.

Based on questions asked during a one-hour argument before the justices, it appeared the court could be heading toward a 4-4 deadlock, with the four liberal justices backing hearings and the four conservatives against hearings.

A 4-4 split would leave in place an October 2015 ruling by the San Francisco-based 9th U.S. Circuit Court of Appeals that upheld a lower-court injunction requiring a hearing after six months of detention.

The long-running class action litigation brought by the American Civil Liberties Union includes some immigrants who were held at the border when seeking illegal entry into the United States and others, including legal permanent residents, who have been convicted of crimes.

The court could avoid a tie by delaying action on the case until Trump appoints a new justice to replace conservative Antonin Scalia, who died in February and the Senate subsequently refused to act on President Barack Obama's nominee to replace him. The justices could then rehear the case.

(Reporting by Lawrence Hurley; Editing by Will Dunham)