The fight to rein in NSA surveillance stalled in the Senate Tuesday evening—meaning the lasting impact of the months-long reform effort will be less about the agency and more about the presidential aspirations of Sens. Rand Paul and Ted Cruz.

Ironically, it was Paul, the libertarian icon, who helped sink the bill to curb America’s most notorious intelligence agency—all in the name of deep-sixing the surveillance state. And he did it with arguments that many civil libertarians found disingenuous, at best. Meanwhile, Cruz, the senator with the reputation as a political arsonist, was suddenly thrust into the role of the insider, looking to fix the NSA from within the system. It didn’t work.

The NSA reforms, known as the USA Freedom Act, are championed by Democratic Sen. Patrick Leahy and Republican Rep. Jim Sensenbrenner. On Tuesday evening, it failed to reach the 60 votes required to advance the bill procedurally.

The bill would have ended the NSA’s bulk collection of metadata, first brought to public knowledge by Edward Snowden; created a special advocate position to argue against the government in the FISA courts; and allowed tech companies to release statistics about government demands for information. Cruz is a co-sponsor of the bill, along with libertarian-minded Sen. Mike Lee.

But the bill would have also reauthorized several Patriot Act provisions until 2017, which Paul said he couldn’t stomach.

“They put something good in a bill that I find objectionable,” Paul told The Daily Beast before Tuesday’s vote. “They could take out the [Patriot Act] reauthorization, then I’ll vote for the bill.”

Paul’s framing of the bill is somewhat misleading: Most sections of the Patriot Act don’t have an expiration date, and don’t need to be reauthorized. The USA Freedom Act would have extended an expiring authority that allows the NSA to search business records, while reforming it to end bulk surveillance and allow tech companies to hold data, rather than the government. (Doug Stafford, a senior Paul aide, emailed The Daily Beast to say "Senator Paul said, repeatedly, that the bill was not simply an NSA reform bill, that it also as part of the bill, reauthorized other expiring parts of the Patriot Act. That is not an opinion. It is a fact. To describe that as misleading is, ironically, itself misleading. Some people may have thought that was worth the trade off; That's a debatable point. But he didn't believe that could vote to reauthorize the Patriot Act, which is what he would have been doing had he votes yes.")

While some opposed the bill for going too far in hollowing out some of the NSA’s capabilities, Paul has the distinction of being the only Republican to vote against the bill because, he said, it did not go far enough.

In 2011, Paul sent a letter to his colleagues, that asked: “Do the many provisions of this bill, which were enacted in such haste after 9/11, have an actual basis in our Constitution, and are they even necessary to achieve valid law-enforcement goals?”

That same year, Paul tussled with Majority Leader Harry Reid on the Senate floor over the issue.

For those observing Paul in recent months, surveillance may seem like the sole issue on which he will not compromise in order to appeal to more traditional conservatives.

As the Kentucky senator has continued to gain steam ahead of the GOP primaries, he has moved toward the center on issues of national security, in what looks like an effort to shake his reputation as an noninterventionist. In September, Paul raised eyebrows when he announced he would support airstrikes in Iraq and Syria against ISIS. That was after vocally opposing engaging in Iraq’s civil war in June, saying he did not want to “turn America into Iran’s air force.”

While Paul’s position on ISIS has not apparently cut into his libertarian-leaning base of supporters, his unwillingness to budge on the Patriot Act, ironically, may undermine it. The libertarian stalwarts at Reason magazine called Paul’s stance a “mistake” Civil-liberties crusaders like privacy-rights lawyer Kevin Bankston were furious at the Kentucky senator. “Rand Paul has a lot of explaining to do,” he tweeted.

Paul and Cruz have a complex relationship. When the former engaged in his drone filibuster, Cruz showed up in support; ditto for Paul when Cruz held an Obamacare filibuster.

But with the midterm elections over and presidential positioning season underway, it seems unlikely the two possible frontrunners for the nomination will put on a united front again soon. Their opposing views on NSA reform is expected to be the first of many clashes as they vie for the affections of Republican primary voters.

While Paul can count as his base anti-Patriot Act diehards, Cruz won’t be trying to appeal to libertarian hipsters in his presidential bid. Instead, the coalition that Cruz will court includes traditional conservatives—especially those who, after nearly a decade and a half of war, may be open to libertarian thinking on intelligence and foreign policy. Call them moderate libertarians.

His co-sponsorship of the bill puts him between Paul, who was unsatisfied with it for not going far enough to cut back the Patriot Act, and and GOP hawks like Sen. Lindsey Graham, who fear it went too far in reining in government surveillance capabilities.

“I don’t like the bill, I’ve never liked the bill, and I’m going to everything I can to kill this and start over again next year,” Graham told The Daily Beast. “This bill guts the ability to defend ourselves when we’re very much at risk. I don’t like the substance of the bill. Start over next year.”

Cruz spokeswoman Catherine Frazier explained, “We’ve been working to make sure the legislation strikes the right balance between upholding American rights to privacy and upholding national security—which is what Americans expect.”

Cruz built a reputation on confrontation. But lately, he’s been sounding a different tune—and looking for ways to further bulk up his legislative achievements. His work on the NSA reforms gives him that, in a way that hits the right notes with moderate libertarians: trying to restrain the NSA, albeit in limited ways.

In Austin on Election Night, Cruz expressed his “hope and intention to work with anybody, Republican or Democrat, to solve the real problems facing this country.” The NSA reform bill falls in this mold, his office argues.

“Cruz has repeatedly shown willingness to work with the other side, with members who don’t always see eye to eye with him, on issues where we can find agreement,” Frazier said. “Those who say otherwise aren’t looking at the facts—case in point is what we’re working on this week.”

Cruz’s spokeswoman called Paul an “important partner” and said the Texas senator would “continue working alongside him to advance policies that will uphold the Constitution, preserve individual liberty, and help turn our country around.”

But according to Paul’s camp, he and Cruz have not been collaborating closely on this issue at all.

Asked before the vote if Paul would be disappointed in Cruz if the NSA reforms passed, Stafford told The Daily Beast: “He will only have feelings about whether Senator Paul supported the bill or not. He’s only responsible for himself.”

“I believe that Senator Paul and Senator Leahy are probably working more closely together [than he is with Cruz],” Stafford said.

It’s a seemingly odd statement, since Leahy was the author of the NSA reform bill Paul just knifed. “We worked with them [the Leahy team], both to try to get the larger Patriot reauthorization parts removed, and to improve some of the reforms,” Stafford added in an email. We didn’t get them to where we wanted. That doesn’t mean both of us weren’t trying to work together.”

This story has been updated to include additional comment from Doug Stafford.