Hillary Clinton picked up fresh support from a group of congressional black lawmakers Thursday, boosting her in her effort to lock down minority voter backing in the face of a serious electoral threat from Bernie Sanders.

The endorsement from the political action committee for the Congressional Black Caucus comes ahead of Clinton and Sanders’ first debate since the Vermont senator clobbered her in Tuesday’s New Hampshire Democratic primary.

The two debate Thursday night in Milwaukee, Wis., a forum hosted by PBS.

“It’s a very big deal,” House Democratic Leader Nancy Pelosi said of the CBC PAC backing.

Rep. Gregory Meeks, in announcing the endorsement, said Thursday Clinton has been a long-term partner who understands the racial divide. The announcement came at a news conference at Democratic Party headquarters in Washington. The PAC is separate from the Congressional Black Caucus, not all of whom have endorsed Clinton.

The Clinton campaign is banking on minority voter support as it heads into South Carolina and other delegate-rich states down the primary calendar. But in New Hampshire, she lost to Sanders across almost every demographic, including women.

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Overall, she lost to Sanders by more than 20 points.

Though Clinton by most accounts delivered a strong performance at their pre-New Hampshire debate a week ago, the pressure is on once again for Clinton to give voters a reason to support her candidacy. Exit polls in New Hampshire showed voters looking for a candidate who’s honest and trustworthy went overwhelmingly for Sanders.

Clinton has acknowledged she has “work to do” to introduce herself to young women and new voters.

But she showed at the most recent debate she’s more than willing to turn up the heat on Sanders, questioning his high-cost domestic proposals and challenging his campaign’s critiques of her record.

Last week, she castigated him for an "artful smear" that insinuated big donors have bought an alliance with her on public policy.

Unclear is whether Sanders, who absorbed the blows last week and rarely got too tough on Clinton, will hit back this time.

Meanwhile, Sanders’ Granite State win has triggered a windfall for his campaign fundraising.

His campaign confirmed Thursday that Sanders has raised $7.1 million since Tuesday.

The Clinton campaign blasted out their own fundraising appeal complaining they were “outspent 3-to-1 on television in New Hampshire, and we need to make sure that doesn't happen again.”

The Associated Press contributed to this report.