Rubio, Cruz Have Fierce Exchange Over Illegal Immigration Policies at CNN Debate

Republican presidential rivals and Senate colleagues Marco Rubio (R., Fla.) and Ted Cruz (R., Texas) had a fierce exchange over their different illegal immigration policies at Tuesday night's debate.

At the outset of their lengthy back-and-forth, Rubio was asked by CNN moderator Dana Bash about his support for the 2013 "Gang of Eight" immigration reform bill, which many conservatives have hit him over as support for amnesty for illegal immigrants.

"The American people don't trust the federal government to enforce our immigration laws," he said. "We will not be able to do anything on immigration until we first prove to the American people that illegal immigration is under control, and we can do that. We know what it takes to do that."

Rubio said 20,000 new border agents, more fencing, a mandatory e-verify system and prevention of visa overstays would be necessary, as well as an update of the legal immigration system.

"After we've done those two things, I think the American people are going to be very reasonable, with what do you do with someone who's been in this country for 10 or 12 years, who hasn't otherwise violated our laws, because if they're a criminal they can't stay," Rubio said. "They'll have to undergo a background check, pay a fine, start paying taxes, and ultimately they'll be given a work permit, and that's all they're going to be allowed to have for at least 10 years."

Rubio said that third step can't be achieved without getting to the first two. Bash said Rubio hadn't answered her question, however, asking if the path he described ended with citizenship.

"After all of that has happened … I personally am open to allowing people to apply for a green card," Rubio said. "That may not be a majority position in my party, but that's down the road … More than ever we need to prove to people that illegal immigration is under control."

Cruz was then asked by Bash about Rubio's comments that Cruz's position was similar to his on immigration.

"There was a time for choosing, as Reagan put it, where there was a battle over amnesty, and some chose, like Senator Rubio, to stand with Barack Obama and Chuck Schumer and support a massive amnesty plan," Cruz said. "Others chose to stand with Jeff Sessions and Steve King and the American people and secure the border."

Cruz connected the immigration problem and border security with the broader issue of national security, and he said one of the more "troubling aspects" of the Gang of Eight bill was that it gave President Obama "blanket authority" to admit refugees without mandating background checks.

"When you're letting people in, when the FBI can't vet them, it puts American citizens at risk, and I tell you, if I'm elected president, we will secure the border. We will triple the border patrol, we will build a wall that works, and I'll get Donald Trump to pay for it," Cruz said, smiling.

Cruz got a slap on the back from Trump as the crowd laughed at the joke. Rubio hit back at Cruz, saying he supported legalization of people in the U.S. illegally, while Cruz shook his head on the split-screen.

"Ted Cruz supported a 500 percent increase in the number of H-1B visas, the guest workers that are allowed into this country, and Ted supports doubling the number of green cards," Rubio said. "What's important for us to understand is there is a way forward on this issue that we can bring our country together on, and when I'm president I will do it. It will begin by bringing illegal immigration under control and proving it to the American people."

Cruz said Rubio's charge was not accurate and trumpeted his fight against Rubio's Gang of Eight legislation.

"He was fighting to grant amnesty and not to secure the border," Cruz said. "I was fighting to secure the border, and this also goes to trust. On campaign trails, candidates all the time make promises. Marco said he learned that the American people didn't trust the federal government. He campaigned in Florida promising to lead the fight against amnesty and he did exactly the opposite."

Rubio spoke over Cruz, asking him directly if he would rule out supporting legalization for people in the country illegally.

"I have never supported legalization, and I do not intend to support legalization," Cruz said.