This post has been updated to reflect progressive Pramila Jayapal's win in a Washington state congressional primary, a win that ups Sanders's record in endorsing congressional candidates. 

When he endorsed Hillary Clinton and spoke on her behalf at the somewhat-contentious Democratic convention last month, Sen. Bernie Sanders (I-Vt.) pledged "to do all that I can" to make sure she defeated Donald Trump this fall. Since the convention, his new group, "Our Revolution," seems to be devoting its energy to … defeating the Democratic Party establishment that backed Clinton.

Hillary Clinton’s campaign comes to an end

MANHATTAN, NY - The morning after loosing to Republican Nominee Donald Trump in the general Presidential election, Democratic Nominee for President of the United States former Secretary of State Hillary Clinton, accompanied by former President Bill Clinton, Chelsea Clinton, Senator Tim Kaine and Anne Holton, speaks to supporters and campaign staff in a packed ballroom at The New Yorker Hotel in midtown Manhattan, New York on Wednesday November 9, 2016. (Melina Mara/The Washington Post)

Sanders has sent at least two emails to his army of grass-roots supporters since the convention ended, asking for money to continue his "revolution," a critical element of his primary-season pitch. The emails mentioned the Democratic National Committee, former committee chair Rep. Debbie Wasserman Schultz (D-Fla.), the Democratic Party, and the Democratic establishment multiple times. They did not mention Clinton, Trump or the Republican Party (which would need to suffer a crushing defeat for Democrats to gain the majority Sanders would need for his progressive priorities to make it through Congress.)

Wasserman Schultz has a Sanders-endorsed primary challenger Aug. 30, who is trying to capitalize on the recent intraparty drama to unseat her. Several polls have shown Tim Canova eight to 10 points behind Wasserman Schultz, with a majority of voters who have never heard of him.

"This race is very important for Our Revolution," read an email Sanders's team sent Tuesday afternoon, "because if we can win this tough fight in Florida, it will send a clear message about the power of our grassroots movement that will send shockwaves through the political and media establishments."

It might well do that. It would definitely settle a primary-season score.

Wasserman Schultz, you'll recall, resigned as head of the Democratic National Committee after emails from the organization leaked on the eve of the convention, and many suggest that supposedly neutral Democratic Party officials were actively trying to undermine Sanders late in the presidential primary.

Sanders says as much in his fundraising email Tuesday: "The recent emails leaked from Democratic Party staff showed that under Debbie Wasserman Schultz, DNC staff were not exactly fair and even-minded during the presidential primary."

But Sanders declared war on the Democratic establishment by endorsing Wasserman Schultz's primary opponent, Canova, a law professor, months before the emails leaked — while his own presidential primary was still going on.

Of course, building off his primary success appears to be a top priority for Sanders well after the primaries are over.

As it became increasingly clear he wasn't going to win the nomination, Sanders launched an endorsement blitz supporting state and congressional candidates across the country. So far, his record isn't great: He is 2-for-4 when it comes to major congressional candidates he's endorsed. And two of those — breakout progressive star Zephyr Teachout, who won her June primary for a swing seat in New York's Hudson Valley, and Pramila Jayapal, who advanced to her general election in the Seattle area — also had the backing of numerous other progressive groups.

Which is what makes the Wasserman Schultz primary so crucial for Sanders. He needs to notch a clear, undisputed win if he wants to keep the enthusiasm going around his revolution, and to silence the naysayers.

Sanders will be 78 when the next presidential campaign comes around, an unlikely age to attempt to launch another revolution in the form of a presidential campaign, so he could be in legacy mode. Perhaps after 2016's congressional primaries are over this month, his focus will shift to the presidential race.

But right now, at least, it appears that solidifying his legacy seems more important to Sanders than helping Clinton win the White House.

In the meantime, shortly after Tuesday's Sanders email …