For leftists and progressively minded Democrats still reeling from Bernie Sanders’s defeat, this week’s elections were very welcome news indeed.

In what can only be called an historic electoral upset, formerly homeless nurse and Black Lives Matter activist Cori Bush defeated the scion of a half-century-old political dynasty to to secure the Democratic nomination in Missouri’s 1st congressional district. Meanwhile, in a race that had been framed by parts of the media as tight, incumbent Congresswoman Rashida Tlaib was handily reelected against challenger Brenda Jones in Michigan.

With 87 percent of precincts reporting on Wednesday morning, the Associated Press called the contest for Tlaib — who will cruise to victory by a double-digit margin. The scale of Tlaib’s win is notable given the recent history of the district, which has seen no less than three congressional primary races since 2018: a special contest to replace veteran representative John Conyers, following his resignation (which Jones narrowly won) and two regular elections, the first of which Tlaib won with a narrow margin of only nine hundred votes.

Between 2018’s close contests and the Super PAC money flowing into Jones’s campaign coffers there was at least some reason to believe the race might be close — the New York Times framed it as “the fight of [Tlaib’s] political life.” With a margin of victory that may yet surpass 30,000 votes, Congress’s most unapologetically left-wing member has put any lingering doubts about her popularity or her longevity to rest.

The night’s biggest upset, however, clearly goes to Bush — who lost her 2018 race against incumbent William Lacy Clay by 20 points. Having represented Missouri in the House since 2001, Clay has many allies in Congress and a family with deep roots in the district (his father, Bill Clay, who held the seat between 1969 and 2001, also cofounded the Congressional Black Caucus). As recently as a few days ago, he was reportedly confident of victory.

The race will rightly be seen in the context of other recent insurgent wins, notably that of Jamaal Bowman against Eliot Engel in New York’s 16th congressional district in June (Bowman, incidentally, endorsed Bush). Nonetheless, despite some obvious parallels, a somewhat different dynamic arguably made the contest an even tougher one for Bush to win.

Clay’s roots in the district clearly set him apart from Engel, who hadn’t faced a competitive primary challenge in decades and whose absenteeism became an issue in the election. Far from exhibiting the same complacency, he mounted a vigorous reelection effort including negative mailers and attack ads and allies in Congress, notably the Congressional Black Caucus, were loud and outspoken in their support.

As Ross Barkin points out, many of the elected officials and groups that aided in Bowman’s victory failed to get behind Bush — a part of the story that is almost certain to be left out of many accounts of the race:

The narrative of Cori Bush’s stunning upset in Missouri won’t include a few inconvenient facts: that Bush, who rose to prominence as an organizer during the Ferguson protests in 2014, unseated a longtime incumbent, Lacy Clay, without the help of Ocasio-Cortez, Elizabeth Warren, MoveOn, PCCC, Indivisible, the Working Families Party, or any of the national progressive institutions who have helped fuel other insurgencies that seemed, to outsiders, much more winnable. Bush’s only well-known backers, beyond her district, were Bernie Sanders and the Sunrise Movement, which also helped Booker early in his race, and Justice Democrats, the young organization that helps launch left-wing challengers from the ground up.

Sanders’s involvement in the race itself became a contentious issue, with one member of the Congressional Black Caucus calling his endorsement “political trespassing.” In their only public statement since Tuesday’s election, the Clay family even blamed “outside money from sources associated with Bernie Sanders” for their son’s defeat.

On election night, Bush herself was unapologetic: “We’ve been called radicals, terrorists. We’ve been dismissed as an impossible fringe movement,” she said during her victory address. “But now we are a multi-racial, multiethnic, multi-generational, multi-faith mass movement united in demanding change, in demanding accountability, in demanding that our police, our government, our country recognize that Black lives do indeed matter.”

In her own victory remarks, Tlaib said much the same, remarking in a statement: “We have a resounding mandate to put people before profits. Let it be known that in the 13th District, just like in communities across our country, we are done with establishment politics that put corporations first.”

Summing up the spirit of what appears a growing political insurgency, she added: “I think it’s safe to say the Squad is here to stay, and it’s only getting bigger.”