Signs of the stress the Democratic Party is under are evident in the degree of institutional fracturing.

Sanders has created what amounts to his own party organization, Our Revolution, which endorses candidates — a signal to voters of Sanders’ backing and of its separation from the Democratic Party. In a revealing statement of purpose the organization declares that

Our Revolution will empower the next generation of progressive leaders by inspiring and recruiting progressive candidates to run for offices across the entire spectrum of government.

For candidates “inspired by the ‘political revolution,’ ” Our Revolution promises to provide

the unparalleled digital tools, organizing knowledge and grassroots support successfully utilized throughout Senator Sanders’ campaign.

Wariness, if not downright hostility, dominates relations between Our Revolution and the Democratic Party.

The tensions between the two are rooted in the disclosure during the 2016 primaries that leaders of the D.N.C. favored Clinton while privately disparaging Sanders’ bid. In February of this year, Thomas Perez, the candidate favored by the Democratic establishment, beat Keith Ellison — who was endorsed by Sanders and who has a strong following among the party’s progressive wing, as well as among its African-American constituency — in the election to become chairman of the D.N.C.

Further compounding the conflict, Sanders has declined to share his donor lists with the Democratic Party.

“We are working hard to regain trust,” Jess O’Connell, the new executive director of the D.N.C., said in a phone interview, although there appears to have been no letup in the tension between the party and the Sanders camp.

In June, the Nation conducted an interview with Nina Turner, a former Ohio State Senator, who is now president of Our Revolution. In April 2016, Turner had famously objected that “brand loyalty” was causing African-American voters to support Hillary Clinton.

The Nation asked:

How will Our Revolution relate to the DNC, the DCCC, the DSCC, that kind of establishment that so many activists and politicians, including you, have frequently criticized?

Her reply:

I don’t think it is our job nor our obligation to fit in. It’s their job to fit in with us.

Then:

And what about the Democratic Party at large. Do you see Our Revolution working to bring some unity to factions in the party?

Turner’s reply:

No, not really. I want people to be unified. I would say that the board of directors wants that too, but we’re here for a very specific purpose, and that is to help the everyday Americans in this country who feel left behind.

Two months later, in August, relations remained hostile.

Buzzfeed reported that in an interview, Turner described the D.N.C. as “dictatorial,” “arrogant,” “pompous,” “superficial,” “tone-deaf,” “tone-dead,” “out of line,” “insulting” and “absolutely insulting.”