“We can’t believe what we’re seeing. It’s like the 2004 primary repeating itself,” one adviser said. “There are definite differences. But the pattern looks really similar.”

Warren’s campaign declined to comment, but a Buttigieg adviser said the sniping was worse in 2004.

“The Gephardt-Dean contretemps makes this look like a love fest — I think people forget how truly nuclear that whole thing was,” the adviser said. “But, more importantly, it takes two to tango on these things. We have zero desire to stoop to her level.”

None of the Democratic campaigns want an identical replay of the 2004 race, of course. Kerry won the nomination, but President George W. Bush won reelection.

Bob Shrum, Kerry’s 2004 adviser, cautioned that while “the parallels aren’t perfect,” there are similarities between the two campaigns.

“We decided we weren’t going to run any negative ads because it would benefit someone else,” Shrum said. And just as Biden is running as the best candidate to beat President Donald Trump, Kerry made that a centerpiece of his messaging.

“We needed to position Kerry as the person [who was] plausibly presidential and had the real chance to beat Bush,” Shrum said. “It’s not just a murder-suicide pact that helped Kerry win. It was the way Kerry positioned himself.”

As in 2004, the 2020 race isn’t a three-person contest. Bernie Sanders, who hails from Dean’s home state of Vermont, is a top-tier candidate as well, just as John Edwards was 15 years ago.

Even before Warren and Buttigieg started to mix it up, she was compared to Dean. Both are from New England (she’s the Massachusetts senator; he was a governor from Sanders’ home state of Vermont) and were the darlings of the educated progressive elite. He started to fade in December. And so has she.

“If I were Elizabeth Warren, I’d put a portrait of Howard Dean on my bedroom wall just so I was reminded every morning: all glory is fleeting,” said David Yepsen, the former dean of the Iowa press corps, who served as political reporter on The Des Moines Register for more than three decades.

“It’s the lesson of Howard Dean, and it’s happened in other caucuses, two frontrunners start fighting with each other and it helps a third candidate come from behind,” Yepsen said.

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“Candidates may want to mix it up and be scrappy with each other — in an ordinary campaign, that would be OK. But this is a campaign where some people are looking for something normal. They’re sick of all of this combativeness. If you’re off to the side and someone else is duking it out, you can look pretty presidential.”

Dean likened Kerry’s establishment campaign then to Biden’s posture now. But in the December before his caucus, Dean said, he was well ahead of Kerry; Biden, by contrast, is polling far closer to Buttigieg, Warren and Sanders in Iowa.

Plus, Dean said in an interview, “Elizabeth is much better organized than we were. I think the best two organizations in Iowa are Elizabeth and Buttigieg.”

But the risks of repeating 2004 are there, he said.

“When two candidates attack each other in a multi-candidate race, the people who are not in the middle of all the attacks are the ones that do better,” Dean said. “And that was one of the big problems with my campaign, we attacked Gephardt in Iowa — which I didn’t know anything about — on television, and that was not a very smart thing to do because that brought both of us down.”

“If Buttigieg and Warren are going at it,” Dean concluded, “that probably helps Biden and probably helps Bernie too.”

