Facing discontent and unheeded warnings from longtime supporters that he could lose the New Hampshire primary, Sen. Bernie Sanders of Vermont on Sunday replaced the director of his presidential campaign operations in the state that holds the first primary in the race for the White House

The campaign broke the news on Sunday to more than 40 members of Sanders’ steering committee. The campaign announced that Joe Caiazzo was being replaced as state director.

Shannon Jackson, who made the announcement, will replace him. Jackson ran Sanders’ 2018 Senate re-election campaign and was a senior adviser on the independent senator’s 2016 White House bid as well as the current campaign.

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“Thank God the campaign finally figured out they had to make serious changes in New Hampshire,” a longtime Sanders backer who attended the meeting told Fox News.

The move comes as some Sanders supporters in New Hampshire are looking over their shoulders at Sen. Elizabeth Warren of Massachusetts - the other progressive standard bearer in the record-setting field of Democratic presidential candidates.

Recent polls in the state have fluctuated. A live telephone operator survey from the Boston Herald and Franklin Pierce University indicated Sanders at 29 percent, overall front-runner and former Vice President Joe Biden at 21 percent and Elizabeth Warren at 19 percent. But another recent poll suggested a three-way tie between the three top-tier contenders and a third suggested Sanders lagging behind Biden and Warren.

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Sanders campaign manager Faiz Shakir said in a statement on Sunday that "we’ve built a great team in NH and are in a really strong position there. The campaign is now building out our operations to include Massachusetts and Maine state directors as we increase our focus in Super Tuesday states. We are running a 50 state campaign, taking no state or voters for granted and expanding our operations to secure the Democratic nomination."

Caiazzo was moved to one of those Super Tuesday states – Massachusetts. Caiazzo served as Sanders campaign’s 2016 state director in both Massachusetts and Rhode Island.

But Shakir’s statement runs counter to what another steering committee member, who also asked for anonymity, emphasized.

Pointing to the campaign, the supporter said “they didn’t listen to anything the steering committee suggested.” The supporter also lamented that some “Bernie backers” were going to Warren because the campaign “didn’t listen to them.”

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Sanders has repeatedly refrained from calling New Hampshire a “must win” state.

“This is obviously a very important state, as is Iowa, South Carolina. We’re working hard. We’re going to do many, many rallies around the state, and I’m feeling pretty good,” he said during a stop in the state on Labor Day.

But, a veteran Granite State-based political scientist said the first primary state’s crucial to both Sanders and Warren.

“New Hampshire is a must-win-or-place state for Senators Sanders and Warren,” said Wayne Lesperance, the vice president of academic affairs and a political science professor at New England College. “For both candidates, there is no better home-field advantage in the early states than the Granite State.”

Sanders trounced Hillary Clinton in the state’s February 2016 Democratic presidential primary, launching the one-time longshot into an epic and marathon battle with the eventual nominee. Sanders’ support and organization in the state stayed very strong, even he ended his first White House bid. His steering committee has met monthly ever since the 2016 general election. But the 2020 race is a very different contest, and Sanders is now facing rivals who are preaching the same progressive policies that he first made mainstream in the Democratic Party four years ago.

The transfer of Caiazzo to Massachusetts and of Jackson to New Hampshire came a day after the campaign parted ways with senior New Hampshire adviser Kurt Ehrenberg.

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“From the very beginning there was clear and fundamental disagreement between Mr. Caiazzo and myself on how to run a successful presidential primary campaign in New Hampshire,” Ehrenberg told Fox News on Sunday.

Ehrenberg, a longtime grassroots and labor organizer, set up the crucial New Hampshire organization for Sanders’ first White House bid from scratch in the spring and summer of 2015.