FILE: Republican presidential candidate Sen. Rand Paul, R-Ky., addresses the Sunshine Summit in Orlando, Fla., Saturday, Nov. 14, 2015. (AP Photo/John Raoux)

LAS VEGAS -- Rand Paul had come with a warning: The forces of spying and surveillance were back, and running wild in the Capitol.

"They're ready to come after your phone records again," said the Republican Kentucky senator to more than a hundred supporters at his campaign office near the airport. "They're ready to come after your credit card records. I promise you, there's a clamor. On the left they're saying they want your guns; on the right they're saying they want your phone records."

Less than 24 hours earlier, in a video address to a hawkish conservative conference, Sen. Ted Cruz (R-Tex.) had warned almost the same thing -- with a bit more Sturm und Drang.

"There are some on both the right and left who want to exploit our current crisis by calling on Americans to surrender our liberties," said Cruz. "On the right, there are some who've called for resurrecting the NSA's bulk metadata collection. But more metadata is not better data. Hoarding the data of law-abiding citizens did not stop Boston, it did not stop Garland, Texas, and it did not stop San Bernardino."

Paul, who endorsed Cruz in the latter's 2012 Senate primary, has fallen far behind him in polls. Just as frustratingly, Cruz has made hard sells to the "liberty movement" voters who backed Paul's father, former Texas congressman Ron Paul, in his two presidential bids, portraying himself as a fusion candidate who got the big issues right and can actually win the nomination.

Tuesday night's main debate will pit seven defenders of surveillance against just two of its critics -- and Paul is trying to win that two-man race.

"[Sen. Marco] Rubio put forward a $200 billion increase in military spending not offset by cuts, and Cruz supported that," Paul told the Washington Post after the rally. "Cruz has voted for reauthorization of the PATRIOT Act. Even though the debate over the NSA was complicated, and there were some reforms in the bill, the underlying bill that Cruz voted for was ultimately a reauthorization of the PATRIOT Act, and that's why I ultimately opposed it."

Those distinctions have generally been lost in an increasingly panicked debate about domestic surveillance. In July 2013, after NSA whistleblower Edward Snowden revealed the scope of the agency's data collection, an NBC News poll found 56 percent of voters worried that the government was going too far in its surveillance. This month, in the wake of the San Bernardino shootings, just 40 percent worried about that, and a clear majority wanted the government to do what it took to catch terrorists.

That mood even permeated Rand Paul's rally. "The surveillance issue -- that's really complicated," said Mark O'Green, 62. "Look what ABC News broke yesterday, that the government had a policy in place to prevent agents from checking Facebook and social media when investigating people."

He was referring to a story about a heretofore unknown prohibition on vetting the social media of visa applicants. Paul, who has called for restricting any foreign visitors from nations with major terrorist presence, has constantly said that the problem with bulk metadata collection was that it was not targeted enough at actual, potential terrorists.

"They're saying, oh, we'll stop terrorism if we collect your records," Paul told the crowd in Vegas Do you know at this moment they are collecting 95 percent of your credit card records? Through the Boston tragedy, through the Paris tragedy, through the San Bernardino tragedy, they were collecting all the records."

Back in Washington, both Paul and Cruz may end up confronting a vote to restore the metadata program restricted in post-Snowden reform bills. In interviews this week, some of the (relatively few) Republicans who had joined them in those votes said they were ignoring the debate until it got serious.

"This is all politics, and I'm not paying a lot of attention to what the candidates say," said Sen. Dean Heller (R-Nev.)

"Frankly, I was convinced -- and still am -- that what was done there was not a violation of anyone's civil liberties," said Sen. Jeff Flake (R-Ariz.). "I was concerned that it was not effective. If there's some other program to collect metadata that's more effective, I'll look at it."

Back in Las Vegas, Paul was portraying himself as the one Republican who would stand and fight any rollback of reform -- and that voters who cared about this should stick with him, despite the bad polls.

"Remember, 13,000 votes could win in Nevada," he said. "Don't let the polls discourage you. We saw Carson fall 20 points in two weeks. The same could happen to Trump."