Senate Republicans blocked an effort to overhaul the National Security Agency's controversial data mining program on Tuesday.

In a 58-42 vote, Republican senators prevented a bill that would have ended the NSA's bulk collection of telephone records from being presented on the floor for a debate. Although the bill received bi-partisan support, it fell short of the Senate's 60-vote threshold.

Championed by privacy advocates, civil libertarians and the White House, "The USA Freedom Act" would have required the NSA to ask a communications company for permission to pull the records of a terror suspect instead of indiscriminately sweeping up records. However, most of the opponents--40 Republicans and one Democrat--argued that the bill went too far.

Senate GOP Leader Mitch McConnell said he voted against the bill because he believed that the reform measures would jeopardize American safety against terrorist groups like the Islamic State.

"If our aim is to degrade and destroy ISIL, as the president has said, then that's going to require smart policies and firm determination. At a minimum, we shouldn't be doing anything to make the situation worse," McConnell said during a Senate speech on Tuesday morning, according to Reuters.

"They cannot cite a single example of this program being abused," said GOP Leader Marco Rubio, referring to the bill's supporters, reports Politico. "Not one. We are dealing with a theoretical threat."

Unlike the majority of the opponents, libertarian leader Sen. Rand Paul claimed that the bill did not go far enough to protect citizen privacy rights. He also criticized the bill for extending the Patriot Act provision that allows the NSA to search Americans' phone records.

After the vote, he said that he "felt bad" about his vote against the motion. "They probably needed my vote," he said It's hard for me to vote for something I object to so much."

However, the bill co-sponsor, Sen. Patrick Leahy, said the legislation extended the provision's expiration to June 2017 and that phone company records could only be searched with a surveillance court's order.

"It would help address the problem of the American government spying on its citizens without cause," said Lee on the Senate floor before the vote. "What opponents of this bill fail to appreciate is that most Americans are deeply, deeply, concerned about the collection of their personal information."

"It's a carefully crafted bill. Don't wait until next year on this," he added.