Senate Republicans have blocked a bill to grant hundreds of thousands of illegal immigrants brought to the United States as children a chance to gain legal status if they enroll in college or join the military.

Sponsors of what they call the Dream Act needed 60 Senate votes for it, but fell five short. The House passed the bill last week. It was a last-ditch effort to enact it before it Republicans take control of the House from Democrats in January.

Immigrant advocates viewed the measure as a step toward providing a path to legal status for up to 12 million illegal immigrants by focusing on the most sympathetic among them first. Critics called it a back-door grant of amnesty that would encourage more illegal immigration.