*Correction appended.

U.S. Sen. Ted Cruz, R-Texas, is facing increasing scrutiny for his vote five months ago to place new limits on national intelligence programs, legislation that is being cast in a new light following deadly terrorist attacks in Paris. 

The drumbeat was started in earnest last week by U.S. Sen. Marco Rubio of Florida, and on Tuesday, an outside group will breath new life into the attack when it goes on the air in Iowa with a TV ad that says Cruz "voted to weaken America's ability to identify and hunt down terrorists." The group, American Encore, is spending just over $200,000 to run the 30-second spot over two weeks in the Des Moines and Cedar Rapids markets, according to its founder, Sean Noble. 

Cruz's campaign dismissed the ad as a sign of the senator's growing dominance in the race for the White House. The campaign is also pointing to Cruz's belief that USA Freedom Act strikes the right balance between keeping the country safe and protecting individuals' right to privacy.

"Because Ted Cruz is surging in the polls, the Washington cartel is now so desperate, they would openly abandon the Fourth Amendment that protects citizens from unconstitutional searches," Cruz spokesman Rick Tyler said in a statement Monday. "We have to wonder what other parts of the Constitution they would gut."

At a forum last Monday in Washington, Rubio singled out Cruz for voting to "weaken" intelligence efforts when he joined 66 other senators to approve the USA Freedom Act, which banned the bulk collection of data on Americans' phone records, among other things. Rubio was among 32 senators who opposed final passage of the bill. 

Noble, a former operative in the Koch brothers' network who personally supports Rubio, said Cruz's vote amounted to political posturing for a presidential race that was expected to look a lot different then than it does now. 

“At the time, it’s clear that he viewed Rand Paul as his main competition for that wing of the party," Noble said, referring to Cruz's libertarian-leaning colleague in the Senate. "And then [billionaire Donald] Trump and [retired neurosurgeon Ben] Carson showed up and threw that completely into the mix, and so obviously after Paris, everyone wants to take the hardline."

"He can’t talk like Reagan and vote with Obama," Noble added of Cruz. "We need a consistent leader, and American Encore’s tradition has been first and foremost, we need to prepare America for the future to have the encore, and national security is the No. 1 issue on that.”

Noble considers himself a Rubio backer, having co-hosted a fundraiser for the senator last week in his home state of Arizona, where  But Noble said American Encore, which has also gone on the air against Paul, is neutral in the GOP race for the White House. 

Rubio further rubbed in the contrast Sunday on Fox News, saying Cruz has "argued that somehow the government is out there spying on everybody, so we need to gut these programs." Rubio's campaign has aggressively promoted the dustup, eager to corner Cruz as on the wrong side of a national security issue following a terrorist attack in Paris that has left many Americans worried about their own safety. 

Cruz's campaign initially pushed back on the attack by noting three other GOP senators who voted in favor of the USA Freedom Act: Chuck Grassley of Iowa, Kelly Ayotte of New Hampshire and Tim Scott of South Carolina. The trio of senators represent the first three early voting states in the 2016 nominating process. Cruz's aides also pointed out that several members of Congress who have endorsed Rubio supported the law as well. 

In an interview Thursday with conservative radio host Glenn Beck, Cruz called Rubio's focus on his USA Freedom Act vote "a lot of silliness" and charged the Floridian with trying to divert attention from their previous battle over immigration. That dustup centered on Rubio's membership in the so-called "Gang of Eight" lawmakers that in 2013 proposed a path to citizenship for people in the country illegally, an idea that is anathema to many in the GOP base. 

"I understand Marco's campaign's desire — desperate desire — to change the topic from Marco's longtime partnership with Chuck Schumer and Barack Obama to push a massive amnesty program," Cruz told Beck. "Particularly in light of the Paris attacks, a lot of people are wondering, 'Well, gosh, why would he have supported the Democrats in granting citizenship to 12 million people here illegally and not securing our border and opening up our refugee program so more and more potential terrorists could come into this country?'"

"I understand why his campaign desperately wants to change the topic because they've made the decision that his longtime support for amnesty is now politically problematic, but I don't think it's going to work," Cruz added.

In an interview with The Guardian published Sunday, Rubio turned the criticism back on Cruz, who along with U.S. Sen. Rand Paul of Kentucky have pounced on his immigration history since the last GOP debate. "They make that argument to distract from their own record on national security," Rubio told the newspaper. 

The interview was conducted during Rubio's longest swing through Iowa yet, a five-day tour that came as Cruz was also crisscrossing the state. At a rally Saturday evening in Des Moines, Rubio did not mention Cruz by name but kept the heat on members of his own party who "know better than" to support curbs on intelligence programs that could, he said, prevent the next Paris.

The next front?

The line of criticism on intelligence programs appears part of a broader strategy by the Rubio campaign to undermine Cruz's self-styled reputation as a "consistent conservative." On Saturday, a Rubio adviser seemed to preview another front in the offensive, sending out six tweets flagging Cruz's reversal earlier this year on his support for Trade Promotion Authority, known as TPA, the power for President Barack Obama to fast-track trade negotiations. 

The tweets began the day after Cruz said at a town hall in Harlan, Iowa, that he intends to vote against the Trans-Pacific Partnership, or TPP, calling himself "deeply concerned" about the massive trade deal between the United States and 11 other countries. Cruz had previously voiced opposition to the agreement, but the town hall appeared to be the first time he said how he would vote on it. 

"I'm old enough to remember when @TedCruz joined @PaulRyan to write about much he loves TPA and TPP," Rubio policy director Jonathan Slemrod wrote Saturday, linking to a news release from the Cruz campaign promoting an op-ed Cruz wrote with Ryan, now the speaker of the U.S. House, that vouched for both TPA and TPP. 

Despite Cruz's vulnerability on the issue, he has nonetheless used it to separate himself from some GOP rivals. Among them: Rubio, who voted for TPA and wrote in an April op-ed that Congress "must ... pass TPP."

"This is one of the real differences in the Republican primary field," Cruz said in Harlan. "There are a number of Republicans on that stage who supported TPP, who supported TPA. I voted against TPA and I intend to vote against TPP."

Correction: An earlier version of this story gave an incorrect home state for U.S. Sen. Tim Scott. He is from South Carolina.