Illegal, but not necessarily unconstitutional. The Second Circuit was asked to decide whether Section 215 of the Patriot Act authorizes bulk collection of phone records. This was a case about statutory interpretation, in other words, not about the Fourth Amendment. Congress is free to rewrite Section 215 to make it clear that they do want bulk records collection — which, coincidentally, is a hot topic in the House and Senate at this very moment, given that Section 215 is set to expire in less than a month.

Hard choice for the GOP congressional majority, then. Do they double down on metadata collection, betting that federal courts will uphold a new, much broader Section 215 against constitutional challenges? Or do they cut their losses and let the section expire, ending the NSA’s massive phone records haul?

It is the first time a higher-level court in the regular judicial system has reviewed the program, which since 2006 has repeatedly been approved in secret by a national security court.

The court, in a decision written by Judge Gerard E. Lynch, held that the Patriot Act provision, known as Section 215, “cannot bear the weight the government asks us to assign to it, and that it does not authorize the telephone metadata program.”…

The House appears ready to pass a bill next week that would end the government’s bulk collection of phone records, but it has faced resistance from the Senator Mitch McConnell of Kentucky, the majority leader.

A similar bill died in the Senate in November after Mr. McConnell urged Republicans to block an up-or-down vote on it with a filibuster.. Mr. McConnell urged a “clean extension” of Section 215 this time so the program could continue in its present form.

Key quote from the opinion: “Congress cannot reasonably be said to have ratified a program of which many members of Congress – and all members of the public – were not aware,” or at least not aware until Edward Snowden exposed the extent of the program two years ago. The Second Circuit could have also considered whether Section 215 is unconstitutional as written, which would have potentially solved the GOP’s political problem by taking this subject out of the legislature’s hands. Courts typically hold off on issuing constitutional rulings, though, if they can find other reasons for why government action is unconstitutional. In this case, it was a simple matter of deciding that the NSA has read the section far more broadly than it was intended, a conclusion buttressed by the fact that the guy who wrote the Patriot Act, Republican Jim Sensenbrenner, says 215 was never supposed to authorize a gigantic metadata dragnet.

So, for the moment, that dragnet might be legal if Congress says specifically that that’s what it wants. Your move, Boehner and McConnell:

The House Judiciary Committee passed a bill 25-2 last week that would end the bulk collection of telephone and email records under Section 215, instead requiring the government to obtain the records on a case-by-case basis. The White House has signaled support for the measure.

But a number of Senate Republicans have expressed reservations with the curbs, saying it could threaten national security. Senate Majority Leader Mitch McConnell (R., Ky.) has suggested there isn’t enough time left in the congressional schedule to debate a way to replace Section 215 before it expires, and he said several days ago that he is likely to pursue a temporary extension of the program with no changes.

It is unclear if such a measure would pass the House or the Senate, in part because of broad opposition to the program.

McConnell’s in the toughest spot because the House and White House are united in wanting to reform Section 215. And McConnell’s a Rand Paul ally, someone who sought Paul’s help for reelection in Kentucky last year because he feared a primary challenge from Paul’s tea-party constituents. Paul promised just last month to end NSA mass surveillance by executive order on day one as president. Does Mitch the Knife dig in with Senate GOP hawks like Tom Cotton against Obama, Boehner, Democrats, and the more libertarian members of his own caucus? It figures that the one time he decides to play hardball is when his own party’s against him. Maybe he expects that if Section 215 is allowed to live on, the courts will end up resolving this soon enough by finding it unconstitutional. Given the language in today’s ruling about how “unprecedented and unwarranted” it is to believe that everyone’s phone records are relevant to terror probes, you can imagine how the Second Circuit might come down on whether bulk metadata collection is a “reasonable” search and seizure process under the Fourth Amendment.

In fact, McConnell might be able to compromise on this without losing much in terms of NSA capabilities. Read this post at Lawfare from February about what sunsetting Section 215 would, and wouldn’t, mean. The NSA wouldn’t be able to use bulk records gathering in newly launched investigations, but it could claim that the process should continue for investigations begun prior to the sunset. Or the NSA could give up on Section 215 altogether and argue that another statute, one which has no sunset, authorizes bulk records collection, if not quite as broadly as Section 215 does. If Congress is going to end metadata harvesting, it’ll probably take more than one bite at the legislative apple to do it. And that assumes that they’ll know whether the NSA’s complying or not. If not for Snowden, they’d still be in the dark about Section 215.