President Barack Obama. REUTERS/Jonathan Ernst President Barack Obama said in a new interview that Sen. Bernie Sanders' (I-Vermont) presidential campaign is not directly comparable his own 2008 White House bid.

Sanders has been surging in the race against former Secretary of State Hillary Clinton, whom Obama also waged an insurgent campaign against in the 2008 contest.

Politico correspondent Glenn Thrush asked Obama whether he bought into the notion that Sanders was an "analog" for his own candidacy against Clinton eight years ago.

"I don't think that's true," the president replied in the interview, which was published Monday morning.

Obama then heaped praise on both candidates.

"I think they're both passionate about kids having a great education," he said. "I think they want to make sure everybody has healthcare. I think that they both believe in a tax system that is fair and not tilted towards, you know, the folks at the very top. But, you know, they — I think Bernie came in with the luxury of being a complete longshot and just letting loose."

He added: "I think Hillary came in with the — both privilege and burden of being perceived as the front-runner."

Obama did concede, however, that Sanders had "tapped into a running thread in Democratic politics that says: Why are we still constrained by the terms of the debate that were set by Ronald Reagan 30 years ago?"

"Why is it that we should be scared to challenge conventional wisdom and talk bluntly about inequality and, you know, be full-throated in our progressivism?" Obama said. "And, you know, that has an appeal and I understand that."

Hillary Clinton and Bernie Sanders at a debate. NBC/YouTube

Obama said Clinton, in contrast, had adopted a more pragmatic message. Clinton served in Obama's administration for four years after losing to him in the 2008 primary.

"I think that what Hillary presents is a recognition that translating values into governance and delivering the goods is ultimately the job of politics, making a real-life difference to people in their day-to-day lives," he told Thrush. "I don't want to exaggerate those differences, though, because Hillary is really idealistic and progressive."

The Iowa caucus is just a week away, and the various polls — which have been all over the map, showing both Sanders and Clinton with strong, single-digit leads — suggest a close race there. Obama predicted that if Sanders were to win Iowa and then New Hampshire, the second voting state, the Vermont senator would start facing serious scrutiny of his campaign proposals.

"I think that if Bernie won Iowa or won New Hampshire, then you guys are going to do your jobs and, you know, you're going to dig into his proposals and how much they cost and what does it mean, and, you know, how does his tax policy work and he's subjected, then, to a rigor that hasn't happened yet, but that Hillary is very well familiar with," Obama said.

The president later suggested Sanders' candidacy was something like a "bright, shiny object" to voters looking for something new.

"I've gotten to know Hillary really well, and she is a good, smart, tough person who cares deeply about this country, and she has been in the public eye for a long time and in a culture in which new is always better," he said. "And, you know, you're always looking at the bright, shiny object that people don't, haven't seen before. That's a disadvantage to her."

Obama continued: "Bernie is somebody who — although I don't know as well because he wasn't, obviously, in my administration, has the virtue of saying exactly what he believes, and great authenticity, great passion, and is fearless. His attitude is, 'I got nothing to lose.'"

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