The Senate approved a comprehensive immigration reform bill by a 68-32 vote on Thursday afternoon. The bill now moves to the Republican-led House of Representatives, where it faces an uncertain future.

The bill gained support from key Republicans thanks to a $46 billion provision to militarize the U.S.-Mexico border. However, many Republicans said the provision was not enough to offset the 13-year pathway to citizenship for undocumented immigrants the legislation would provide.

Fourteen Senate Republicans joined Democrats to approve the bill.

"The Senate’s passage of immigration reform legislation is important but just one step in a long march towards justice. Today's vote should send an unmistakable signal to the House of Representatives to take action to move immigration reform forward, delivering a real solution to our broken immigration system," Evelyn Rivera of United We Dream said in a statement.

"Senator Pat Leahy (D-VT) and Senator Harry Reid (D-NV) made passing immigration reform a top priority and worked with leaders from both parties to move the bill quickly through the Senate," she continued.

"Now it’s up to Speaker Boehner to follow suit—pass immigration reform with a real roadmap to citizenship this year. So far, his caucus has voted for extreme anti-immigrant legislation and slammed DREAMers by undermining the Deferred Action for Childhood Arrivals Program. House leaders have an opportunity to get on the right side of history and will have to answer to DREAMers, and voters, if they don’t."