Sen. Patrick Leahy (D-Vt.) declared victory Tuesday after the U.S. Senate signed off on sweeping changes to the nation's surveillance laws. 

The USA Freedom Act, he said in a written statement, "will enact the most significant reforms to government surveillance powers" since Congress passed the USA Patriot Act in the aftermath of the attacks of September 11, 2001. The bill bars the National Security Agency from collecting bulk metadata from telephone companies and requires a court order for the information to be obtained, among other changes.

Passage of the USA Freedom Act restored certain surveillance powers that have been on hold since Sunday, when portions of the Patriot Act expired and Sen. Rand Paul (R-Ky.) held up consideration of the new legislation.

Opposing the bill Leahy helped write was his fellow Vermont delegate, Sen. Bernie Sanders (I-Vt.). He and Sen. Tammy Baldwin (D-Wis.) were the only liberals to join 30 Republican senators in voting "nay." Sixty-seven Democrats, Republicans and independents voted for the bill.

In an interview on NBC's "Meet the Press" on Sunday, Sanders indicated he was inclined to vote for the bill, which passed the U.S. House last month with Congressman Peter Welch's (D-Vt.) support. 

"I may well be voting for it," he told moderator Chuck Todd. "It doesn't go as far as I would like it to go."

When Todd asked if he was comfortable with telephone companies storing the data, as would happen under the USA Freedom Act, Sanders said, "No, I'm not, but we have to look at the best of bad situations."

Sanders sounded a different note Monday in an interview with Yahoo News' Katie Couric.

“I voted against the Patriot Act. I voted against the reauthorization of the Patriot Act. And I will vote against final passage for the current legislation, because I think it does not go far enough," he said.

Sanders struggled to explain specifically what portions of the USA Freedom Act he opposed, or what sort of surveillance legislation he might support. Instead, he focused on big-picture complaints with the modern surveillance state.

“I honestly believe that we will give the government and law enforcement all of the resources that it needs to go after those people that we have to go after," he told Couric. "But I worry, really worry, that we are moving toward an Orwellian form of society where big brother, whether in the corporate world or in the government, knows — has too much information about the private lives of innocent people.”

Asked to explain Sanders' apparent change in position between Sunday and Monday, spokesman Michael Briggs said, "He hadn’t decided on Sunday how he would vote on a measure that he said is better than the current law but doesn’t rein in the NSA as much as he wants. So on Sunday he still was weighing the pros and cons. By Monday, he had decided on balance to vote no."

Correction: An earlier version of this story misidentified Sen. Rand Paul's home state. He is from Kentucky.