Carolyn Kaster / AP

On June 1, the spying stops.

Not all of it, of course, but after the stroke of midnight on that Monday morning the National Security Agency must halt some of the spying programs it launched in the months and years after September 11, 2001. And not because it wants to, either, but because several key provisions of the Patriot Act will expire without congressional action, and lawmakers can’t agree on how much of the surveillance state to keep in place. (June 1 is, of course, still more than a week away, but much like the objects in car mirrors, deadlines in Congress are usually closer than they appear.)

The House last week voted overwhelmingly to approve legislation to reauthorize the Patriot Act while ending the NSA’s bulk collection of telephone metadata and instituting reforms aimed at making the secretive agency more transparent. With its business completed, the House left the Capitol for a Memorial Day recess, with no plans to return before the afternoon of June 1st—hours after the deadline.

The Senate, however, remains bitterly divided on the issue. A majority of senators support the House bill, dubbed the USA Freedom Act, but one of its staunchest opponents is the man in charge, Majority Leader Mitch McConnell. He believes the Patriot Act should be extended without changes, even though most senators are adamantly opposed to a clean reauthorization. McConnell allowed the House bill to come up for a vote shortly after midnight Saturday, but it fell three votes shy of the 60 it needed to overcome a filibuster. GOP national-security hawks like Lindsey Graham and Richard Burr oppose it, and enough Republicans stuck with McConnell to prevent the Senate from getting steamrolled by the House.

McConnell’s own bid to pass a two-month extension to buy time to negotiate a compromise also fell short, and senators wouldn’t allow him even to approve an extension of 24 hours. Because the House had already skipped town, it might have been a moot point, and it probably wouldn’t prevent a temporary spying slow-down at the NSA. “You can’t extend something that is dead,” declared Senator Patrick Leahy, the Vermont Democrat, in a floor speech Friday. With McConnell backed into a corner, lawmakers like Democrat Ron Wyden of Oregon and Republican Dean Heller of Nevada say they won’t support anything except the Freedom Act—not even the shortest of time-buying Patriot Act extensions. Burr, who heads the Senate’s Intelligence Committee, tried to break the impasse on Friday by proposing legislation that mirrored the House bill but provided a longer transition for the NSA to end its bulk collection program. It also sought to address concerns that the telephone companies wouldn’t retain data they would be newly charged with collecting in place of the government.

And then there’s Rand Paul, the presidential hopeful who delivered a 10-hour speech-but-not-a-filibuster on Wednesday to protest a reauthorization of the Patriot Act, which he called “the most unpatriotic of acts.” Paul also opposes the House’s Freedom Act on the grounds that it doesn’t go far enough to curb surveillance. On this point he joins other privacy advocates who point out that the NSA would still be able to access metadata from phone companies and are concerned that the proposal contains too many legal loopholes. Early Saturday he made a point of objecting to any extension of the Patriot Act unless McConnell committed to having a broader debate on the merits of the spying programs.

So the Senate is essentially stuck, and the Obama administration, which supports the Freedom Act, isn’t offering much help. Ratcheting up pressure on McConnell, the Justice Department sent a memo to Congress warning lawmakers that even if they delay action until the weekend, they may be too late to avoid an interruption in surveillance—the programs can’t just be turned off like a light switch. “After May 22, 2015, it will be increasingly difficult for the government to avoid a lapse in the current NSA program of at least some duration,” the memo said. McConnell announced that the Senate would return to session on Sunday, May 31—just hours before the deadline—to figure out what to do.

What this all means for the security of the nation remains unclear. Privacy advocates believe the country would be better off if the entire Patriot Act was left to expire, while supporters of the surveillance programs argue that any interruption would put American lives in danger. “The intelligence community needs these tools to protect Americans,” McConnell said on the Senate floor on Friday. Come June 1, the country could find out if he’s right.

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