Marco Rubio thinks he has Ted Cruz right where he wants him: on the wrong side of national security politics after a harrowing terrorist attack. 

The Florida senator and his aides are pounding Cruz for his support of surveillance reforms that became law this spring over the objections of Rubio and old-school defense hawks. 

It’s a calculated risk to say that Cruz weakened national security: Many Republicans sided with him in a vote that split the party over how to balance surveillance reforms with national security. But the Rubio campaign believes this is its opening to expose Cruz as being in step with Democrats on an issue that will drive the next three months of the campaign. 

Late Tuesday afternoon, Cruz fired back, saying that Rubio is trying to distract from his record of working on the Senate’s comprehensive immigration bill, the subject of a protracted dispute between the two campaigns over the past week. 

“It is not surprising that Marco’s campaign wants to change the topic from Marco’s partnership with President Obama to push a massive amnesty program,” Cruz said with a theatrical chuckle. “I understand politically why they want to change the topic from that, but I don’t think they’re going to be successful.” 

On Tuesday, Rubio and his team went all in, painting Cruz as weak on national security, an attack line that seizes on growing unease in the United States since the Paris attacks. In brief remarks after a closed Senate Intelligence Committee briefing on the Paris attacks, Rubio stood by his comments the night before that Cruz and a number of other GOP senators had voted to “weaken” national security and intelligence gathering. 

“It eventually undermines our ability to collect information and to monitor those who seek to harm the United States,” Rubio said. 

Asked why he singled out Cruz among the 67 senators who ultimately voted for the reforms, Rubio replied: “We have a race for commander in chief, and the most important obligation of a president is to keep our country safe.” 

Still, Rubio’s comments made life awkward for several of his surrogates who supported the USA Freedom Act, which enacted changes to the surveillance dragnet that the Florida senator opposed. Rubio has been endorsed by a trio of his colleagues in the chamber, including Sens. Cory Gardner of Colorado and Steve Daines of Montana, who backed the USA Freedom Act. 

In interviews, Gardner and Daines shrugged off Rubio’s comments. Gardner said “people have different opinions” and then knocked Obama’s leadership on Syria; Daines said he backed the legislation because of its privacy protections. 

“But I think Marco Rubio would be a great commander in chief,” Daines added. 

Meanwhile, Cruz’s team quickly pointed out that influential senators from early-voting states supported the USA Freedom Act, suggesting that Rubio is alienating potential supporters in Congress by criticizing their efforts to rein in the bulk data collection programs. 

But other lawmakers, including Sen. Dean Heller (R-Nev.), chafed at Rubio’s attacks on Cruz and the surveillance bill. 

“If the presidential candidates want to talk against your personal liberties, let them do so to their own demise as far as I’m concerned,” said Heller, a supporter of Jeb Bush. 

For the hard-charging Cruz, foreign policy is an area of relative moderation. He likes to say that there are two poles in the party, with Sen. Rand Paul at one end and Rubio and Sen. John McCain at the other. 

To Rubio, the issue is more black and white: You’re either with Paul, or you’re with Rubio. On Tuesday, Rubio’s campaign aides circulated Cruz’s equivocal reactions to the disclosures of national security programs by Edward Snowden, hoping to further paint Cruz as out of step within the GOP. 

Cruz’s campaign deemed the attacks as a distraction from Rubio’s vulnerability on immigration, and an adviser said “our campaign won’t be taking the bait.” 

Still, there was evidence among senior senators that Rubio’s aggressive posture on national security and foreign policy is working. 

“People who have extensive experience on national security issues and intelligence issues right now are going to have an advantage,” said Sen. John Thune (R-S.D.). “Marco has sort of staked out for some time pretty strong positions on those issues, and I think he’s well-positioned to make the arguments.” 

Added Sen. Dan Coats (R-Ind.): “Marco is right on it, and he’s got the intelligence to be right on it.” 

Rubio and Cruz have warily eyed each other on national security for years. They voted together for a filibuster of Chuck Hagel’s nomination as defense secretary in 2013 but have experienced high-profile breaks as well: When Paul forced a vote on cutting aid to Egypt in 2013, Rubio spoke against it, while Cruz sided with Paul. 

Paul and Cruz were the only Republicans to oppose a compromise national defense policy bill last month, another area in Cruz’s record that Rubio’s team believe is ripe for inspection. And senior Republicans are still annoyed at those votes. 

“I have a number of differences with Sen. Cruz. And I have some with Sen. Rubio. But it was disturbing to me when Sen. Cruz voted against the defense authorization bill,” said McCain, an Arizona Republican. “I view that as a slap in the face to the men and women who are serving.” 

Cruz is best known for insulting McConnell and being among the most conservative senators on practically any topic. But on surveillance reform he joined a bipartisan coalition early on, charting a middle course between Paul, whose views are to the left of much of the GOP, and Rubio, who Cruz believes is too close to McCain’s position. 

It’s a difficult balance. Cruz is trying to court both the libertarian voters associated with Rand Paul and his father, former Rep. Ron Paul, and more mainstream conservatives. But on Tuesday, Cruz stood by his vote on the surveillance bill and said conservatives across the country are more concerned with privacy issues than Rubio would like to believe. 

“I’ll tell you, conservatives care about the Bill of Rights, care about protecting the privacy of law-abiding citizens and also about protecting our national security,” Cruz said. “At the end of the day, this issue all comes down to their campaign’s desire to change the subject from Marco’s support for amnesty.” 

Many Republicans bristled during the debate over government surveillance at how the program was portrayed. Senators close to the intelligence community said there had been no abuses. But the idea of extending the bulk data collection with no changes, supported by Rubio, couldn’t even get a majority in the Senate, much less clear the chamber’s 60-vote requirement. 

The issue turned senators who often vote against anything that smells of compromise into pragmatists; on this issue, Rubio was the hard-liner, not Cruz. 

“It was the only thing we had. Without it, we’d have nothing. It was what you had to do,” said Senate Homeland Security Committee Chairman Ron Johnson (R-Wis.). “But I was highly concerned about the weakening of our intelligence-gathering capabilities. I still am.” 

“I have no second thoughts,” added Sen. Tim Scott (R-S.C.), who also backed the bill. “There is an important equilibrium to be found between weighing privacy and national security.”