Republican Presidential Debate

Marco Rubio: I'm concerned about a debt crisis

Sen. Rubio: Need more deep policy questions
Top issues at stake: Sen. Rubio
Harwood's post-debate analysis

GOP presidential candidate Marco Rubio said Thursday entitlements need to be reformed immediately so the financial burden of keeping the underfunded Social Security and Medicare programs afloat won't cause a debt crisis.

"The longer we wait, the likelihood increases that we're going to have a debt crisis because right now we're paying the historically low yields on American debt. If that just goes up to the normal historic number, and some time it will, then we're going to have a debt crisis," the Florida senator told CNBC hours after the third Republican debate in Colorado.

"We're going to be spending more money on servicing the debt than we are on our own military," he continued. "We know it's coming. You just can't predict when."

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Rubio said he wants to make changes to Social Security and Medicare to save the programs for his generation. He said people near retirement would be unaffected, and acting now can avoid making the changes too disruptive.

Appearing on CNBC's "Squawk Box" hours after his strong debate showing, Rubio said he was a "little tried," but added he was pleased with his performance.

In a topic he wanted to spend more time on during the debate, he noted Thursday that wages have not climbed fast enough in the U.S., and workers need to be better trained for the higher-paying jobs of the new economy.

Rubio also reiterated his call for corporate tax reform.

The Democratic argument on corporate tax reform has been "raise the tax on something else," he said, arguing that such a move would be counterproductive. "That's where the rub comes."

"Congress can help shape an agenda, but only president can set it," he added, saying that's why he's running for the White House.

Pundits said Rubio had a good night, connecting with voters on the issues, defending his personal finances, and rebutting Jeb Bush's criticism over the Florida senator's absences from votes on Capitol Hill.

Taking a shot Wednesday at Democratic front-runner Hillary Clinton, Rubio said she got a free pass by the media in coverage of her testimony about the deadly embassy attack in Benghazi.

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Rubio's national numbers have been climbing, and according to the RealClear Politics polling aggregator, he's third behind Donald Trump and Ben Carson. Bush, a former Florida governor, is in the No. 4 position.

A new national Tuesday found that Carson had edged out Trump for the lead. Carson has been surging in the early presidential contest state of Iowa, leading Trump in most local polls there.