If you’re Bernie Sanders, it doesn’t seem like it would be much of a choice whether to campaign with the Democrat running for re-election in New York City or with the Democrat running for governor in Virginia.

In New York, Mayor Bill de Blasio is up by roughly a gazillion points, and doesn’t need Sanders to excite the Democratic base.

In Virginia, Ralph Northam is in a tight race against a Republican running fear ads about immigrant gangs running amuck and Confederate statues supposedly representing our way of life. A pediatric neurosurgeon, a veteran, and Virginia’s current lieutenant governor, Northam is capable and credentialed. But he’s not charismatic, and he could use a little help from his friends.

Yet Sanders campaigned Monday with de Blasio, in a race where he isn’t needed, even as he’s refused to endorse Northam in one where he could have a significant impact. Our Revolution, the advocacy group founded by Sanders, has endorsed six candidates running for the Virginia House of Delegates but isn’t playing in the governor’s race.

“They’ve done nothing, and it’s a shame,” says a Democratic strategist with Virginia roots. Wary of escalating the tensions between the Hillary and Bernie wings of the party, he doesn’t want to be named.

“This race is really the first battle for the resistance, and it’s dangerous for our prospects going forward if we can’t win this.”

State Democrats suffering from PTSD after the 2016 election are nervous history could repeat itself with angry voters overtaking the broader electorate and electing Republican candidate Ed Gillespie, the former RNC chairman who’s gone to the gutter with a torrent of 30-second TV ads offering dark, Trump-like takes on cultural issues.

President Obama campaigned last month in Richmond for Northam, trying to motivate African-American voters in that majority black city. A Sanders endorsement would help energize the Democratic base. The Brooklyn-born Sanders inspires young voters in a way that eludes the soft-spoken Northam who grew up in rural Virginia.

“If we come up short, people are going to assess those who chose to sit on the sidelines,” says the Democratic strategist. “There will be serious questions asked about why they did it. If the answer is that they took a pass on this race because the candidate wasn’t from their team,” that won’t sit well, said the party strategist.

Sanders has held off on endorsing the Democrat after Northam defeated his pick, former Rep. Tom Perriello, in the primary. Perriello, though, quickly backed Northam, as did DNC Chair Tom Perez, who told reporters at a breakfast Tuesday organized by the Christian Science Monitor that “our unity is our biggest strength.”

All of which makes Sanders’ behavior all the more puzzling. Some Democratic loyalists went so far as to call Sanders their Steve Bannon, meaning he will happily sink more mainstream and establishment Democrats to make a point. What that point is, exactly, has Democrats in Virginia scratching their heads. “Northam is the most progressive candidate for governor in Virginia, versus the epitome of what they (Bernie’s progressives) say they hate,” says the Democratic strategist, pointing out that Gillespie’s career as a lobbyist makes him one of the “swamp creatures” that Trump likes to ridicule even as he stacks his White House and his Cabinet with swamp denizens.

To get the big picture, I called Bill Galston, a political scientist with the Brookings Institution, who reminded me that Bernie Sanders is not a Democrat, that he became one solely for the purpose of running for president, and he isn’t one anymore. “He’s loyal to a movement, and he’s loyal to a set of ideas. He’s not loyal to a party, and he’s unconcerned by the progress Democrats care about that he might impede. Incremental change is not the business he’s in,” says Galston.

It’s a hard truth that Hillary Clinton confronted after spending months battling Sanders in last year’s primaries. She saw campaigning as a chance to lay out “a road map for governing.” He saw the campaign as an opportunity to mobilize a movement, not to get every jot and tittle right about the big changes he was calling for in the tax code or to provide free college.

Will he pay a price if Northam loses and the number crunchers say another percentage point or two of turnout among millennials could have made the difference? First, as President Obama learned in 2016, and in the midterm elections when his name wasn’t on the ballot in 2010 and 2014, it’s very difficult to transfer your support and your star power to someone else.

“Will some disappointed Democrats be upset that he wasn’t there when it counted? Sure,” says Galston. “But Sanders is working to increase the size and intensity of the movement he helped found, and he’s not in the business of making compromises at this point.”

Galston dismissed the idea of any comparison between Bannon—who wants to take a wrecking ball to established GOP positions on trade, immigration and America’s place in the world—and Sanders, who endorses the direction of the Democratic Party but wants to hasten its approach.

“I see Senator Sanders as working to radicalize the Democrat Party, not to re-direct it,” says Galston.

“He’s saying things he’s believed since he was an adolescent in Brooklyn and finally he’s getting someone to listen—so why not! It’s not any more complicated than that.”