Story highlights Supporters of bill that would curb NSA fail to get supermajority of 60 votes

White House, liberal Democrats and some libertarian Republicans supported the bill

Senate Republican Leader Mitch McConnell led the charge against the bill

Under bill, government could no longer keep large amounts of call information in its databases

Republican opponents of White House-backed legislation that would rein in NSA surveillance programs narrowly blocked the Senate from taking up the bill Tuesday after warning it could help terrorists escape detection.

On a tally of 58 to 42, a procedural vote failed to get the supermajority 60 votes it needed to advance.

Supporters of the USA Freedom Act, a rare mix of liberal Democrats and libertarian Republicans, hoped public outrage over the secret mass collection of phone and Internet records -- revealed by former NSA contractor Edward Snowden -- would lead to passage of the reforms. But many opponents argued the changes would hamper the National Security Agency's ability to track nimble and elusive terrorists.

Senate Republican Leader Mitch McConnell led the charge against the bill, saying the new rules would prevent the United States from capturing the terrorists who killed Peter Kassig, a U.S. citizen doing aid work in Syria. Kassig was executed over the weekend.

"Many of these fighters are familiar with America's intelligence capabilities, and many are savvy with communications. These are terrorists who know how to use encryption, and they how to change devices quickly," he said. "This is the worst time to be tying our hands behind our backs."

"It basically takes us back to a pre-9/11 lack of capacity to identify terrorists making telephone calls in the United States, said Sen. John Cornyn of Texas, the second-ranking Senate Republican. "I think that sort of unilateral disarmament would be bad for the country."

McConnell also argued the measure should be debated and voted on in the new Congress next year, not by lawmakers in a lame duck session who are leaving Washington.

Sen. Patrick Leahy, D-Vermont, the bill's principal author, disputed the critics saying that while it puts checks on the NSA's powerful capabilities, it "does so responsibly."

"The bill contains key reforms to safeguard Americans' privacy by prohibiting the indiscriminate collection of their data. It also provides for greater accountability and transparency of the government's surveillance programs," he said. "The bill also ensures that the intelligence community has the tools it needs to keep our country safe."

Under the bill, the government could no longer store massive amounts of call information in its databases, a practice President Barack Obama said he wanted to end. That job would fall to the large telecommunication companies. But the government could get permission from a secret surveillance court to review specific call information if it could show it might be linked to terrorists.

Sen. Dianne Feinstein, D-California, who chairs the Senate Intelligence Committee, said this arrangement "solves" a "very practical problem" raised by those who are uncomfortable with the government storing calling records of Americans.

But Sen. Susan Collins, R-Maine, said the public's privacy would be better protected by strict federal government safeguards of that information than by the thousands of employees at private phone companies.

In a statement Monday, the White House urged passage of the bill.

"This legislation will help strengthen Americans' confidence in the government's use of these important national security authorities. Without passage of this bill, critical authorities that are appropriately reformed in this legislation could expire next summer. The administration urges Congress to take action on this legislation now, since delay may subject these important national security authorities to brinksmanship and uncertainty."

The bill is supported by a coalition of technology companies, including Google, Apple, AOL, Microsoft and Yahoo, who have deep concerns that their customers' privacy is being violated by the current NSA techniques.

Supporters suffered a setback last week when Sen. Rand Paul, R-Kentucky, who had favored the measure, announced he would not back it. However, other like-minded Republicans such as Sen. Ted Cruz of Texas and Sen. Mike Lee of Utah voted to advance the bill.