Sanders will likely announce an exploratory committee in the coming weeks, followed by a rally. One major early focus will be finding a campaign manager and other top-level staffers who are not white, and preferably not male, in light of his problems appealing to minority voters in 2016 and recent revelations of sexual harassment by lower-level staffers on the 2016 campaign. Staff interviews have been quietly under way.

But a core team of advisers will return from 2016, spearheaded by Sanders’s wife and closest adviser, Jane O’Meara Sanders.

Peter Beinart: Bernie Sanders offers a foreign policy for the common man

His aides know this race will be different from his 2016 run against Hillary Clinton, when he surprised even himself with how close he came to knocking her off. Democratic leaders have been impressed by the extent to which the ideas from his campaign have carried forward, injecting far-left populism into the mainstream of Democratic politics—even as many in the party still bitterly point to his candidacy as weakening Clinton to the point that Trump was able to win.

Sanders has heard the argument that his stature would be diminished by running again if he doesn’t end up winning the nomination. He’s heard the argument that he might split the progressive vote and allow a more moderate candidate to win, but that hasn’t moved him either. That’s not how Sanders thinks, people who know him point out.

“He understands what happens in the streets is what prompts actions in Washington,” said Vincent Fort, a former Georgia state senator who supported the last campaign and has been in touch with Sanders’s team about this campaign.

There are also the nuts-and-bolts political considerations that Sanders doesn’t focus as much on, but that his team pays close attention to: He’s the one with the massive email list. Alone among those eyeing the Democratic nomination, he’s the one who had 40,000 people watching various live-streams of his State of the Union response. He’s the one whose team thinks he could, on day one, raise more money online and get more attention than any of the other candidates.

Sanders believes that he continues to have the strength in Iowa and New Hampshire to either win or come close there—especially with other candidates fragmenting support and lowering the bar for what it will take to win. Likewise, in a South Carolina primary that has both Cory Booker and Kamala Harris competing for African American votes and, likely, Joe Biden drawing on his own decades of connections there, Sanders sees a path to slip through and win.

Biden in the race, after all, would make it so that the senator isn’t the only white man in his 70s in the field.

If the early states all come together, Sanders would be positioned to power through the front-ended primary calendar that has California, Texas, and several other big states voting on the first Super Tuesday, March 4, just a month after Iowa. No one else in the field has anything like his proven success with both grassroots supporters and the small-dollar online fundraising that it will take to fund the kind of massive national operation any 2020 campaign will require.