The Center for Popular Democracy Action, a coalition of more than 50 progressive groups, on Tuesday announced it was endorsing Sen. Bernie Sanders (I-Vt.) in the Democratic presidential primary race.

Sanders received 75 percent of the votes cast by groups in the coalition's network to pick a candidate to back in the organization's first-ever presidential endorsement, the group said.

"Bernie Sanders is the powerful movement candidate we need to defeat Donald Trump. From ending mass incarceration and deportations to the $15 minimum wage and Medicare for All, Sanders is working hand-in-hand with our communities to champion the policies that we need to thrive," Jennifer Epps-Addison, co-executive director and network president of the coalition, said in the announcement.

"The dignity and safety of immigrant communities, communities of color and working-class people are on the ballot in 2020. In endorsing Senator Bernie Sanders, our network has chosen a champion for people who have been historically forced to the margins," co-executive director Ana Maria Archilla added.

The coalition had narrowed the 15-person field down to three candidates: Sanders, Sen. Elizabeth Warren (D-Mass.) and former Housing and Urban Development Secretary Julián Castro (D-Texas) in November.

The vote was later narrowed to Sanders and Warren, the top two after a November vote in which none of the candidates received 60 percent of the vote, the necessary threshold for an endorsement, the organization said.

Center for Popular Democracy has a group of 53 affiliates and partners in 131 cities across 34 states, as well as Puerto Rico and Washington, D.C.

Sanders said he was proud to be endorsed by the organization.

"Together we're going to build a movement for racial, social and economic justice made up of working class Americans that will bring millions of people together and transforms our country so it works for all of us," Sanders tweeted Tuesday.

The endorsement comes as Sanders and Warren continue to battle for progressive endorsements. The senators have broken into the top tier of the race, along with former Vice President Joe Biden and South Bend, Ind., Mayor Pete Buttigieg, who are pitching more moderate agendas.

Warren received the backing of the influential progressive Working Families Party in September. The Working Families Party had endorsed Sanders in his 2016 White House bid.

--Updated at 10:46 a.m.