With the first presidential nominating contests less than a month away, every endorsement counts — and Sen. Bernie Sanders (I-Vt.) just snagged a big one. Members of the liberal advocacy group MoveOn.org voted overwhelmingly to support Sanders' bid for the Democratic presidential nomination. Of the 340,665 votes cast in its internal endorsement process, the organization said, Sanders won 78.6 percent. 

"This is a massive vote in favor of Bernie Sanders, showing that grassroots progressives across the country are excited and inspired by his message and track record of standing up to big money and corporate interests to reclaim our democracy for the American people," MoveOn.org political action committee executive director Ilya Sheyman said in a statement circulated by the Sanders campaign. 

The MoveOn endorsement represents "boots on the ground" in the Iowa Caucuses and the New Hampshire primary. The organization pledges to turn out its 43,000 members in the Hawkeye State and its 30,000 members in the Granite State.

In December, Sanders received an endorsement from another liberal advocacy group, Democracy for America. But his chief Democratic opponent, former secretary of state Hillary Clinton, has generally outperformed him in the endorsement game, winning nods from far more elected officials and most national labor unions. Just last weekend, the Planned Parenthood Action Fund announced its support for her candidacy.

According to the latest polls, Sanders and Clinton are neck-and-neck in Iowa and New Hampshire. A new poll released Tuesday by Monmouth University showed Sanders faring even better. It found that the Vermont senator had opened up a 14-point lead over Clinton in neighboring New Hampshire, besting her 53 percent to 39 percent.