Sanders leads polls ahead of New Hampshire primary, while Buttigieg climbs and Biden nosedives

William Cummings | USA TODAY

Show Caption Hide Caption Democratic debate post-Iowa had candidates trading blows in New Hampshire The debate between the Iowa caucuses and New Hampshire primary had some Democratic candidates landing blows, and some making strides.

Sen. Bernie Sanders continues to lead in polling ahead of New Hampshire's primary Tuesday while former South Bend, Indiana Mayor Pete Buttigieg has surged into second place.

The polls show Buttigieg has growing support from New Hampshire voters while former Vice President Joe Biden has tumbled in recent Granite State polls.

The results from Iowa's caucuses last week are still not official after delays and inconsistencies with the vote count, but Buttigieg's strong finish there appears to have given his campaign a bounce heading into New Hampshire. Buttigieg and Sanders have both declared victory in that unsettled contest, which is undergoing a precinct review that state Democrats said will be completed Monday.

A look at the polls

A poll from CNN and the University of New Hampshire Survey Center released Sunday found that 28% of likely primary voters favor Sanders, while 21% plan to vote for Buttigieg and 12% plan to vote for Biden. Nine percent said they would back Sen. Elizabeth Warren of Massachusetts, 6% said they plan to vote for Sen. Amy Klobuchar of Minnesota, 5% were for Rep. Tulsi Gabbard of Hawaii, 4% backed entrepreneur Andrew Yang and 2% were for billionaire Tom Steyer. The other candidates came in at 1% or less.

A CBS News/YouGov poll released Sunday found the race even tighter, with Sanders the choice of 29% of likely voters in New Hampshire's Democratic primary and Buttigieg favored by 25%. That poll found Warren (19%) in third ahead of Biden (12%) and Klobuchar (10%).

The CBS News and CNN polls were conducted from Feb. 5-8. The CBS News poll had a margin of error of plus or minus 4.3 percentage points, while the CNN poll's margin of error was plus or minus 5 percentage points.

A pair of tracking polls conducted since Friday night's Democratic debate found Klobuchar was the only candidate to get a noticeable boost from her debate performance.

Emerson College's tracking poll with News 7 found Sanders leading at 30% on Sunday, followed by Buttigieg (20%), Klobuchar (13%), Warren (12%) and Biden (11%). That represented a four-point jump for Klobuchar and a four-point drop for Buttigieg from the previous poll, which was conducted before the debate.

A WBZ/Boston Globe/Suffolk University tracking poll – two-thirds of which was conducted during and after the debate – found a three-point boost for Klobuchar to 9% from 6% in the previous day's poll. But she still trailed Sanders (24%) followed by Buttigieg at 22% (down from 25% the day before), Warren (13%) and Biden (10%).

How polls work: The science behind gathering voter opinions The news cycle is jampacked with polls. But have you ever wondered how polls actually work and what they mean?

Candidates go on the attack

With his boost in the polls, Buttigieg has come under fire from both Sanders and Biden.

The 2020 candidates: Who is running for president? An interactive guide

Biden's campaign released an ad on Saturday that paints Buttigieg as an inexperienced smalltown mayor who is unqualified for the White House.

"It's a typical political attack," Buttigieg said on CNN's "State of the Union" Sunday. "And it's too bad, because so many communities, communities like mine in South Bend, we know that we might look small from the perspective of Washington, but, to us, it's what's going on in Washington that looks so small and small-minded."

Biden said on ABC News' "This Week" that he was defending himself from Buttigieg who he said unfairly blamed the Obama administration for many of the country's current problems.

'Stakes are incredibly high': New Hampshire voters feel the pressure as primary looms

"Let's get something straight here," Biden said. "I didn't attack Pete. Pete's been attacking me."

"I don't understand, when they talk about the past, why Barack was such a lousy president. I thought he was a pretty damn good president," Biden said. "But that's the implication."

On CNN, Buttigieg explained that his argument was not meant as a criticism of the Obama administration but a call for a new approach.

"This isn't 2008. It's 2020. And we are in a new moment, calling for a different kind of leadership," he said.

Sanders has gone after Buttigieg for accepting campaign contributions from wealthy and corporate donors.

"If you do, as Mayor Buttigieg does, take huge amounts of contributions from the CEOs of the pharmaceutical industry, from financiers in the fossil fuel industry, from the insurance companies, from Wall Street, does anyone seriously believe that you're going to stand up to those powerful entities and represent working people?" Sanders asked "Fox News Sunday" host Chris Wallace.

"Bernie's pretty rich, and I would happily accept a contribution from him," Buttigieg said on CNN. "This is the fight of our lives. I'm not a fan of the current campaign finance system, but I'm also insistent that we have got to go into this with all of the support we can get."

What we know: A New Hampshire primary win is key for multiple Democrats

In an apparent dig at Sanders, Buttigieg said he was "concerned about a message that says, 'if you're not for revolution, you must be for the status quo,' because I think that leaves most people out."

2020 candidates on the issues: A voter's guide to where they stand on health care, gun control and more