WASHINGTON — The government’s authority to sweep up vast quantities of phone records in the hunt for terrorists expired at 12:01 a.m. Monday after Senator Rand Paul blocked an extension of the program during an extraordinary and at times caustic Sunday session of the Senate.
Still, the Senate signaled it was ready to pass an overhaul of the National Security Agency’s bulk data collection program, one that would shift the storage of telephone records from the government to the phone companies. The House overwhelmingly passed that bill last month. Senators voted, 77-17, on Sunday to take up the House bill.
The stand by Paul, Republican of Kentucky, forced the temporary expiration of parts of the post-9/11 Patriot Act used by the NSA to collect phone records, but he was helped by the miscalculation of Senator Mitch McConnell, the majority leader, who sent the Senate on a weeklong vacation after blocking the House bill before Memorial Day.
McConnell, also of Kentucky, relented Sunday, setting up a final round of votes on Tuesday or Wednesday that will probably send a compromise version of the House bill to President Obama for his signature. Even Paul, using the procedural weapon of an objection, conceded he could not stop that.
“Little by little, we’ve allowed our freedom to slip away,” Paul said during a lengthy floor soliloquy.
The expiration of surveillance authority demonstrates a profound shift in American attitudes since the days after the Sept. 11, 2001, terrorist attacks, when national security was preeminent in both parties.
Fourteen years after that attack, even as conflicts continue abroad, a swell of privacy concerns stemming from both the vast expansion of communication systems and an increasing distrust of government’s use of data has turned those concerns on their head.
Although the House bill would represent a retrenchment on the part of the government, it does not end the argument over the dual imperatives of security and individual liberty brought to light by Edward J. Snowden, the former NSA contractor.
The expiration of three key provisions of the Patriot Act means that, for now, the NSA will no longer collect newly created logs of Americans’ phone calls in bulk. It also means that the FBI cannot invoke the Patriot Act to obtain, for new investigations, wiretap orders that follow a suspect who changes phones, wiretap orders for a “lone wolf” terrorism suspect not linked to a group, or court orders to obtain business records relevant to an investigation.
However, the Justice Department may invoke a grandfather clause to keep using those powers for investigations that had started before June 1, and there are additional workarounds that investigators may use to overcome the lapse in the authorizations.
McConnell and other national security hawks who failed to continue the program badly underestimated the shift in the national mood, which has found its voice with Democrats and the libertarian wing of the Republican Party. The moment also put him at odds with Paul, whom he has endorsed for president.
“I remain determined to work toward the best outcome for the American people possible under the circumstances,” McConnell said. “This is where we are, colleagues — a House-passed bill with some serious flaws, and an inability to get a short-term extension to improve the House bill.”
Paul’s effort clearly angered many of his Republican colleagues, who met without him an hour before the Senate began to vote Sunday night. Senator John McCain, Republican of Arizona, who sparred with Paul on the floor over procedure, said later that Paul was not fit for the White House job he seeks.
“I’ve said on many occasions that I believe he would be the worst candidate we could put forward,” he said.
Even as senators were trickling into the Capitol from the airport, McConnell attempted to extend some aspects of the law.
He asked senators to consider a two-week continuation of the federal authority to track a “lone wolf” terrorism suspect not connected to a state sponsor and to conduct “roving” surveillance of a suspect, rather than of a phone number alone, to combat terrorists who frequently discard cellphones.
But Paul objected, and McConnell denounced from the Senate floor what he called “a campaign of demagoguery and disinformation” about the program.
McConnell then moved to a second option, a procedural move to take up the bill passed by the House, which he said the Senate would amend this week.
It was unclear Sunday how many amendments, including any from Paul, would be considered and whether any could pass the Senate or be adopted by the House.
The House bill would overhaul the Patriot Act and scale back the bulk collection of phone records revealed by Snowden. Under the provisions of the House bill, sweeps that had operated under the guise of so-called national security letters issued by the FBI would end. And data from the phone records would instead be stored by the phone companies and could be retrieved by intelligence agencies only after approval of the Foreign Intelligence Surveillance Act court.
The White House backs the bill. Josh Earnest, the White House press secretary, said in a statement: ‘‘The Senate took an important — if late — step forward tonight. We call on the Senate to ensure this irresponsible lapse in authorities is as short-lived as possible. On a matter as critical as our national security, individual senators must put aside their partisan motivations and act swiftly.’’
CIA Director John Brennan was among those warning that letting the authorities lapse, even for a time, will make America less safe.
Terrorists ‘‘are looking for the seams to operate within,’’ Brennan said on CBS’ ‘‘Face the Nation.’’ ‘'This is something that we can’t afford to do right now.’’
The NSA already had begun winding down the phone collection program in anticipation that it will not be renewed. To ensure the program has ceased by the time authority for it expires at midnight, the agency planned to begin shutting down the servers that carry it out at 3:59 p.m. Sunday. Rebooting would take about a day.
Material from the Associated Press was used in this report.