MANCHESTER, N.H. - A fourth-place finish in Iowa was not what Joe Biden expected.

"I’m not going to sugarcoat it. We took a gut punch in Iowa," the former vice president admitted as he kicked off a campaign event in New Hampshire on Wednesday.

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But Biden emphasized that "this is not the first time in my life I’ve been knocked down" and he vowed to voters in the state that holds the first primary in the race for the White House that "we're going to come back."

The Granite State is now immensely more important for Biden, now that the candidate once seen as the unrivaled front-runner exits Iowa with little wind at his back. But coming back in a state his campaign has long considered the weakest among the four early voting states -- including Nevada and South Carolina -- won't be easy.

With Sens. Bernie Sanders of Vermont and Elizabeth Warren of Massachusetts hailing from neighboring states and enjoying a degree of home-field advantage, the Biden campaign has always seen Nevada and South Carolina -- which directly follow New Hampshire and have a diverse electorate -- as better prospects. And South Carolina, with a majority black electorate in the Democratic presidential primary, has long been considered Biden's firewall.

Biden's team assembled a formidable staff in the first primary state, but seemingly never went all in for New Hampshire. But with his lackluster showing in Iowa -- Biden stands at 16 percent of convention delegates with 97 percent of precincts reporting -- the former vice president needs to crank it up in New Hampshire. Another poor finish could threaten that South Carolina firewall and hurt Biden's ability to catch up to Sanders and former South Bend, Ind. Mayor Pete Buttigieg in the battle for campaign cash. Both of them, along with Warren, are leading Biden in the Iowa returns.

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“Iowa results being muddled in controversy has only elevated [New Hampshire's] importance further for Biden, and what’s on the line for his candidacy -- he cannot afford a weak finish in [New Hampshire] or else voters are going to ask ‘How is Biden going to beat Trump if he can’t win early?' This election is about beating Trump," said Michael Ceraso, a Democratic strategist and veteran of the 2016 Sanders campaign who served as Buttigieg's New Hampshire state director until parting ways with the campaign last summer.

Biden's Iowa performance was far from ideal and far below where some in the campaign believed the former vice president would finish.

“I expected to do better,” the candidate himself said at CNN town hall in Manchester, N.H., Wednesday evening. “And I expected that our organization would perform better.”

As of Tuesday, Biden was roughly spending $200,000 to run ads in New Hampshire in the final week leading up to the primary, according to data from the ad tracking firm Advertising Analytics. That's below every one of his main rivals. But the former vice president got a major lift on Tuesday when the pro-Biden super PAC "Unite the Country" told Fox News that they would be spending $900,000 to run ads in the Granite State.

Those ads will be needed, as the latest polls suggest Biden trailing both Sanders and Buttigieg

Longtime New Hampshire Biden supporter Terry Shumaker, a well-known attorney and consultant in the state and a former ambassador, acknowledged that New Hampshire's going to be more watched now because the results out of Iowa are more muddled. "Even when they get final numbers, they'll still be under a cloud a bit," he said.

And he admitted that "New Hampshire's probably elevated in importance" before noting that "I think our support here is very solid, and I think it's underestimated."

And another top Biden supporter from New Hampshire is longtime Democratic National Committee member Billy Shaheen, who's the husband of Sen. Jeanne Shaheen. He believes New Hampshire was very important for Biden, no matter the outcome in Iowa.

"Even if he had won in Iowa, I don't think he could afford to lose in New Hampshire," he said. "We're working this to win."