AUDIE CORNISH, HOST:
At the outset of this presidential campaign, progressives were torn between Elizabeth Warren and Bernie Sanders. But eventually, in states that have held primaries, they picked a side, and many of them chose Sanders. The story of how that happened explains part of Warren's downfall. NPR's Asma Khalid has that story.
ASMA KHALID, BYLINE: In February of 2015, I went up to New Hampshire to meet a group of Elizabeth Warren superfans. They were trying to draft her into the 2016 presidential race.
UNIDENTIFIED PERSON: When I say Warren, you say run. Warren.
UNIDENTIFIED GROUP: Run.
UNIDENTIFIED PERSON: Warren.
UNIDENTIFIED GROUP: Run.
UNIDENTIFIED PERSON: Warren.
UNIDENTIFIED GROUP: Run.
KHALID: One of the groups behind the effort was Democracy for America. Charles Chamberlain is the chair.
CHARLES CHAMBERLAIN: We believed that she would have been a better candidate than Hillary Clinton.
KHALID: At the time, Warren was adored by progressives as this charismatic star on late night TV who had fought the big banks during the recession. But just last week, Chamberlain's group endorsed Sanders over Warren.
CHAMBERLAIN: The change between that time is that, look, when we were trying to get Elizabeth Warren to run back in 2014, '15, that was before Bernie Sanders had run for president. And Bernie Sanders ran in 2016 an incredible campaign and even moved the entire Democratic Party to the left.
KHALID: Late last summer, when Warren was holding mega-rallies with seemingly never-ending selfie lines, the progressive community was not so sure what to do. In September, the Working Families Party became the first major group to endorse a candidate, and it chose Warren. Here's the group's director, Maurice Mitchell, at a rally in New York City.
(SOUNDBITE OF ARCHIVED RECORDING)
MAURICE MITCHELL: Elizabeth Warren has been a personal hero to many WFP members. Her critique of the financial industry helped lay the groundwork for Occupy Wall Street.
KHALID: Then in October, a blow to Warren. Congresswoman Alexandria Ocasio-Cortez endorsed Sanders.
(SOUNDBITE OF ARCHIVED RECORDING)
ALEXANDRIA OCASIO-CORTEZ: We right now have one of the best Democratic presidential primary fields in a generation, and much of that is thanks to the work that Bernie Sanders has done.
GEORGE GOEHL: You started to see dominoes fall after that.
KHALID: That last voice is George Goehl. He's the director of People's Action, another group that endorsed Sanders. He says his group liked Sanders' authenticity, but they were also focused on electability.
GOEHL: A lot of us believe Senator Sanders is uniquely capable of winning and beating Trump.
KHALID: Some progressive organizations made a point of insisting their endorsements were not because of anything Warren did, but because of Sanders' credibility and consistency on issues like health care and climate change. Still, others, like Natalia Delgado (ph) with the Center for Popular Democracy, says there were a couple of key distinctions.
NATALIA DELGADO: The sort of defining factors for us between Bernie and Warren was his stance on a moratorium of deportations.
KHALID: In recent years, immigration has increasingly become a pillar of the progressive agenda, especially with Donald Trump as president.
DELGADO: Between that and her sort of distancing herself from "Medicare for All," and when she thought she would be able to get it done really, you know, distanced her from our folks.
KHALID: Voters who liked Warren mentioned her plans, but Sanders had a tendency of taking the ideas further. Warren promised a two-cent wealth tax on people with a net worth over $50 million. Sanders upped her and made it $32 million. Warren promised affordable child care. Sanders promised free child care.
Evan Weber is the political director of Sunrise. It's a movement of thousands of young people focused on climate change. They also chose Sanders even though Warren has been a friend of theirs in the Senate. And so I asked him...
If this were, like, a different race in a different context, Warren might have had your guys' backing?
EVAN WEBER: I think that's fair to say, yeah. I mean, I think her presidency would represent one of the biggest step forwards for the progressive movement in the country.
KHALID: In the end, it was a tough decision. But many went with Sanders because they saw him as the purest progressive.
Asma Khalid, NPR News. Transcript provided by NPR, Copyright NPR.