MoveOn, a major progressive public policy group, endorsed Democratic presidential candidate Bernie Sanders on Tuesday morning, announcing that an overwhelming amount of their members "feel the Bern."

In a statement sent to Latin Post, the liberal advocacy organization said that 78.6 percent of more than 340,000 members voted to support the Vermont senator in an online balloting conducted last Thursday through Sunday.

On the other hand, just 14.6 percent voted for Democratic front-runner Hillary Clinton while former Maryland Gov. Martin O'Malley earned less than 1 percent of support. Another 5.9 percent of voters chose not to endorse any candidate at all.

"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 Executive Director Ilya Sheyman said in the statement, adding, "MoveOn members are feeling the Bern."

Sheyman also said the group will now work to mobilize nearly 75,000 of its members in the key early voting states.

"We will mobilize aggressively to add our collective people power to the growing movement behind the Sanders campaign, starting with a focus on voter turnout in Iowa and New Hampshire," added Sheyman.

In response, Sanders said he was "proud" to be endorsed by MoveOn, which has been on the forefront of liberal issues for years.

"MoveOn has spent more than 17 years bringing people together to fight for progressive change and stand up against big money interests," said the self-proclaimed "Democratic Socialist."

"MoveOn's fight to give the American people a voice in our political system was reflected in the group's internal democratic process. I'm humbled by their support and welcome MoveOn's members to the political revolution," he said.

MoveOn endorsed Barack Obama in the 2008 Democratic primary race after 70 percent of its members voted for the former senator compared to 30 percent who supported Clinton.