KEENE, N.H. ― The gloves are really starting to come off just three days away from the critical New Hampshire Democratic primary.

On Saturday, Joe Biden’s campaign released a digital ad mocking Pete Buttigieg over his prior experience running South Bend, Indiana, a city with a population of just over 100,000 residents.

The roughly minute-and-a-half spot is part of an ongoing effort by Biden to contrast his record as Barack Obama’s vice president with that of the 38-year-old Buttigieg, who has been surging in the polls in the Granite State.

“Both Vice President Biden and former Mayor Pete have helped shape our economy. Joe Biden helped save the auto industry, which revitalized the economy of the Midwest. And led the passage and the implementation of the Recover Act, saving our economy from a depression,” the narrator says in the ad. “Pete Buttigieg revitalized the sidewalks of downtown South Bend by laying out decorative brick.”

The blistering attack reflects the Biden campaign’s unease with Buttigieg’s position in the race. The former mayor finished in a virtual tie for first in the Iowa caucuses with Sen. Bernie Sanders (I-Vt.), exceeding predictions, while Biden finished in a disappointing fourth place.

Biden’s campaign has downplayed the importance of New Hampshire in favor of more diverse states like Nevada and South Carolina, where the former vice president has more appeal, but there’s no doubt that another disappointing finish will threaten his path to the nomination.

Buttigieg’s campaign responded to the Biden ad on Saturday by saying that “Washington politics trivializes what goes on in communities like South Bend.”

“The Vice President’s decision to run this ad speaks more to where he currently stands in this race than it does about Pete’s perspective as a mayor and veteran,” Buttigieg spokesman Chris Meagher said in a statement.

Biden campaign digital director Rob Flaherty rubbed salt in the wound: “This video now has more views than the population of South Bend,” he tweeted.

The back-and-forth between the two candidates has heated up in the past few days. At Friday night’s Democratic debate in Manchester, Biden took issue with Buttigieg’s criticism of the old system in Washington, accusing him of calling the Obama administration a failure at a rally in New Hampshire: “Is he really saying the Obama-Biden administration was a failure? Pete, just say it out loud.”

Biden isn’t the only one taking aim at Buttigieg over his experience. Sen. Amy Klobuchar (D-Minn.) also unloaded on him at Friday’s debate, saying, “We have a newcomer in the White House, and look what that got us.”

But Buttigieg largely ignored the attacks during a packed town hall meeting in Keene on Saturday, which his campaign said numbered nearly 1,000 people, citing the local fire department. Buttigieg was introduced by actor Michael J. Fox, who compared him to Obama, and the candidate stuck to his stump speech about bringing people together to take on President Donald Trump.

Undecided voters who showed up to hear Buttigieg’s pitch said they didn’t mind that he had less government experience than the others running for president.

“I love his youth. I love his enthusiasm. I love ― honestly ― his lack of experience because I think he will defer to the right people to help him guide this country,” said Susie Szydlo, 61, who works as a nurse in Dublin.

Larry Phillips, a retired psychologist from Keene, noted that Obama was also criticized for his relative inexperience when he ran for president in 2008.

“How about all the experience Trump had? None. Zero. Less than zero,” Phillips said. “It would be nice if [Buttigieg] had broader political experience, that’s true. I just think he’s smart enough and measured enough that he could handle it.”