Former Ohio state senator Nina Turner is taking the reins of Our Revolution, the political group launched by Sen. Bernie Sanders (I-Vt.) to elect progressive candidates — a move that elevates a dogged critic of the Democratic Party just as Sanders takes a bigger role in its messaging.

In a statement Thursday, Our Revolution announced that Turner would replace Jeff Weaver, Sanders’s 2016 presidential campaign manager and longtime strategist, who is currently serving on the party’s unity commission to reform its primaries.

“We are thankful for the work Jeff has done and look forward to his next project,” said Our Revolution board chairman and former Communications Workers of America president Larry Cohen in a statement. “We’re thrilled that our board member and progressive champion Nina Turner will be our new president.”

In an accompanying video, Turner saluted OurRev’s victories since its founding. “With these hands,” she said, “we will continue to rise.”

But the stylistic differences between Weaver and Turner are vast, symptomatic of the divisions within a left that’s locked out of power and arguing about how to get it back. Turner, who made a splash in 2015 by jumping from Hillary Clinton’s presidential campaign to Sanders’s, has become a superstar among left-wing activists who think the Democrats have become so “corporate” as to raise questions about whether they’re worth saving.

In 2016, despite her time as a Clinton booster, Turner was among the Sanders surrogates most resistant to “party unity.” After Sanders’s Democratic primary bid ended, she speculated whether a “young, new, burgeoning party” would be a better vessel for progressive energy. During the Democratic National Convention, after hackers released a trove of emails from the Democratic National Committee, Turner gave a rousing speech to the left-wing “People’s Convention” attacking staffers who had been revealed as critics of Sanders.

Later that day, Turner learned that she would not be allowed to address the DNC — a decision that became a flash point for Sanders supporters. Some of them marched to the media tents around the convention center to say they’d demanded answers for the snub, which never came.

Turner, meanwhile, remained at the convention as a one-woman Greek chorus of progressive discontent.

“It’s kind of ironic — lots of establishment folks said they didn’t need Sen. Sanders, but it’s clear now that they do need him to pull over as many of his supporters as he can,” she said in one interview with the progressive online network The Young Turks. “People in the DNC are going to need to work hard to earn their vote.”

The Green Party approached Turner to run for vice president in 2016, an offer Turner eventually declined. Instead, she remained a potent progressive surrogate through the election — and after, as Clinton’s defeat discredited the party’s center-left. She frequently appeared on cable news to criticize the party for not being bolder or not centering on people of color. She also launched a talk show on The Real News Network, a progressive online channel, where one of her first guests was Sanders, and where she criticized the Democrats for betting so much on Jon Ossoff’s race for a House seat in Georgia.

“People don’t want a substitute for the real thing,” she said. “That’s what Ossoff was doing — offering a substitute for Republicans.”

Just three days ago, Turner joined a progressive pile-on of California’s Democratic speaker of the House, who bottled a bill to create a state-based single-payer health-care plan at an estimated cost of $331 billion to $400 billion a year.

“What is the difference between the Democrats & Republicans again?” Turner tweeted. “Oh, the difference between the fox & the wolf!”

Our Revolution, which was founded after Sanders’s primary bid ended, has worked entirely inside the Democratic Party. It endorsed the Democrats’ candidates for special elections in Kansas and Montana long before the national party plugged money into them; its highest-profile win this year has been the election of Christine Pellegrino, a 2016 Sanders delegate, to a formerly deep-red-state legislative seat in Long Island.

But Our Revolution, a player in Democratic politics, does not limit itself to supporting one party. This year, it backed long-time Green Party activist Cheryl Honkala for a legislative race in Philadelphia where Democrats bungled their nominating process and ran no candidate; after a Democrat won as a write-in candidate, Honkala filed a lawsuit. OurRev also backed Ali Deng, a progressive city council candidate in Vermont. Sanders himself, the longest-serving independent ever to serve in Congress, has suggested that there will be times where people might do best to run outside the Democratic Party — even as he takes a major role in changing that party from within.