Sanders’ campaign revealed it replaced its former South Carolina state director, Kwadjo Campbell, last month. Caiazzo previously served as Sanders’ New Hampshire state director until September, when he moved to Massachusetts. A Sanders adviser said at the time that he was being reassigned due to his experience in the state and because the campaign was “not conceding Massachusetts to anyone,” an apparent reference to home-state Sen. Elizabeth Warren.

“Joe has been one of our first hires and was critical in building out our N.H. operation,” said Shakir. “We wish Joe nothing but the best in his next endeavor and thank him for playing such a critical role in the beginning of this campaign. Bernie Sanders is going to win New Hampshire and a lot of that credit will go to Joe Caiazzo.”

Caiazzo was the campaign manager for Sen. Sheldon Whitehouse’s 2018 reelection bid and was Rhode Island state director for Hillary Clinton’s 2016 team. He had also worked as Sanders’ political director in Massachusetts and Rhode Island in the 2016 primary.

“Joe has played a critical role in Bernie’s operation in Massachusetts and New Hampshire for a long time now,” said a person familiar with Caiazzo’s situation. “Bernie Sanders needs to be prepared for Super Tuesday. We’ve heard a lot about all the work they’re doing in California, but what else are they doing in the remaining dozen-plus Super Tuesday states to make sure he has a good showing?”

Caiazzo declined to provide comment.

Sanders’ team did not say whether it has hired a replacement for Caiazzo yet. A spokesman did not immediately respond to a question about the number of staff or offices in Massachusetts.

Sanders’ staff has said it is making major investments in Super Tuesday, including hires and a recent seven-figure ad buy that airs in New Hampshire, Maine and Massachusetts.

Caiazzo’s move from New Hampshire in September was part of a larger shakeup of the campaign in the first-in-the-nation primary state. Kurt Ehrenberg, Sanders’ senior adviser in New Hampshire, also left the team at the time. The two aides had clashed. Sanders’ former Iowa political director, Jess Mazour, parted ways with the Sanders campaign over the summer as well.