In another indication of the appeal of the insurgent presidential candidacy launched by Bernie Sanders, a grassroots group that had been organized to draft Elizabeth Warren into the race for the Democratic nomination has transformed into a new organization and endorsed the Vermont senator’s campaign.

“Inspired by Elizabeth Warren’s message that we need to fight—and fight hard—to win the progress we want to see, Ready to Fight is a grassroots group that’s standing with Warren in the fights she’s leading, and backing Bernie Sanders for president in 2016,” declares the website launched by organizers of the Ready for Warren campaign that had been one of several efforts to draft the senator from Massachusetts.

Ready to Fight will advocate broadly for an economic populist agenda that mirrors the messages of Warren with regard to taking on the big banks and addressing income inequality, wage stagnation, and a host of other issues.

Warren has said that she will not seek the nomination, and she has not made a formal endorsement in the race for the Democratic nomination. Many of her backers (including several key players associated with the separate Run Warren Run initiative) are still exploring their options in a race that also includes front-runner Hillary Clinton, as well as former Maryland governor Martin O’Malley and former Rhode Island governor Lincoln Chafee.

But Sanders has surged since announcing his candidacy, drawing large crowds in key states and moving to within 10 points of Clinton in a recent poll of likely voters in the first-primary state of New Hampshire. And in an opinion piece published Friday by CNN, Ready for Warren campaign manager Erica Sagrans and Charles Lenchner, a co-founder of Ready for Warren and the director of Organizing 2.0, wrote:

We believe the movement to draft Warren fundamentally changed the terms of the 2016 debate, and these days, just about every Democrat running for president seems to sound a lot like Warren. Few people have ever played as large a role in a Democratic presidential primary without even entering the race.

But having demonstrated how much support Elizabeth Warren has, we’ve spent the past few weeks listening to our grassroots supporters and the progressive community about what they want to do next. And one thing we heard time and again is that they’re ready to play a big role in 2016, fighting alongside Warren on issues like trade, student debt, and reining in Wall Street.

They are also ready to back “Warren Wing” candidates who embody Warren’s fearless brand of progressive populism. And although it isn’t just about the presidency, 56% of supporters have urged us to back Bernie Sanders as the candidate currently running for president who best embodies the values that Warren champions.

Sagrans and Lenchner explained that “Ready for Warren is launching a new grassroots initiative called Ready to Fight—and Ready to Fight is endorsing Bernie Sanders as its candidate for president” because, “while Warren is the champion who inspired this movement, the draft effort was never just about her—it’s about her message and the values she represents.”

The organizers conclude that “Bernie Sanders has caught fire in a way that’s reminiscent of the draft Warren movement itself—from the Internet to town halls in Iowa, Sanders has captured the imagination and support of people looking for a real progressive challenger in the 2016 Democratic primary.”