"I hope they win," Sanders said. "Maybe they don't. But if you get 45 percent of the vote now, next time you may well win."

"I could be 100 percent in terms of my endorsements," Sanders told NPR. "All you've got to do is endorse establishment candidates who have a whole lot of money, who are 40 points ahead in the poll. You know what, you'll come and say, 'Bernie, you were 100 percent supportive of these candidates, they all won.'"

Even if many of his hand-picked candidates are coming up short, more of the Democrats who are winning are lining up closer to Sanders anyway. A Medicare-for-all, single-payer health care plan continues to gain support among Democratic candidates, and the $15 minimum wage Sanders made a key part of his presidential campaign has been adopted as a cause by party leaders across the country.

"Many of these issues were considered fringe issues, and now they are mainstream issues that we take for granted that there, of course, are legions of Democratic candidates running on those platforms," said Jeff Weaver. "Three or four years ago you would not have seen candidates running on that platform I would have considered to be outside the mainstream."

Unlike the memorable, mega-events from [Bernie Sanders's] presidential campaign, with throngs of mostly young voters, a year and half later this room was made up of 450 fresh-faced, Democratic candidates seeking public office themselves, many for the first time.

The scene Thursday afternoon was a snapshot of the revolution the independent senator always wanted -- or at least the one he hoped for after his bid for the White House fell short -- coming to pass.

Candidates from 48 states, running in races big and small, gathered in Washington, D.C., for a four-day training session to learn tricks of the trade from some of the savviest grassroots organizers in the country with the hope of perpetuating a progressive brand of politics back home in their districts.

Sanders' legacy political organization, Our Revolution, partnered with the Progressive Change Campaign Committee (PCCC) to host the conference and the organizers were excited by the number of signups. According to event representatives, 70 percent of the conference attendees were actively running in 2018 -- 64 percent of them in districts President Donald Trump won in 2016. The group was noticeably diverse too: 55 percent women, 40 percent people of color and 82 percent who have never held political office.