Democratic socialists just unseated three more Democratic incumbents in congressional primaries — and if Democrats take the House by a narrow margin this fall, a handful of DSA-backed radicals could dictate what the majority can or cannot do.
The Democratic machine spent years cultivating the far left. Now it can't control what it built. In Colorado, 29-year-old attorney Melat Kiros knocked off Rep. Diana DeGette, who had held her seat for three decades. In New York, two DSA-endorsed candidates — Darializa Avila Chevalier and Claire Valdez — won House primaries in safely Democratic districts, virtually guaranteeing they'll be seated in January 2027. They'll join existing DSA House members Alexandria Ocasio-Cortez and Rashida Tlaib, along with Sen. Bernie Sanders.
The catalyst is New York City Mayor Zohran Mamdani, who won his 2025 race as a DSA member and has since lent his star power to fellow travelers. Mamdani cut ads for three New York progressives promising to "abolish ICE" and "end corporate greed." All three won their June 2026 primaries.
The New York Times acknowledges the surge but frames it as a youth-driven phenomenon rooted in "dissatisfaction with the status quo, anger over Israel's treatment of Palestinians, concern about the growing affordability crisis." The Times' own data tells a starker story: in Claire Valdez's precinct near the Brooklyn border, she took 84 percent of the vote, and three-quarters of those who cast ballots were under 40. In New York's Seventh Congressional District, younger registered Democrats turned out at a higher rate than older ones — a rarity in primary elections. The Times reports a "strong correlation" between a precinct's average voter age and its support for DSA-backed candidates. What the Times won't say plainly: the party's base is radicalizing, and the establishment that once channeled that energy into reliable votes has lost the leash.
The Boulder Daily Camera, drawing on political science analysis, notes the reckoning is "more complicated than many inside or outside the Democratic Party convey" — affiliation with DSA explains only some of the insurgent wins. But the practical consequence is straightforward: DSA's official membership has nearly doubled since Mamdani's viral mayoral campaign, reaching roughly 100,000. That's a sliver of the electorate, but concentrated in the right primaries, it's enough to move the needle. The Camera notes that if Democrats win the House with a narrow margin, "the cooperation and votes of a handful of DSA members could be crucial to Democrats' ability to act effectively as a majority — or not."
DSA's far-left positions — Medicare for All, defunding police, taxing the ultrawealthy — are toxic to moderate Democrats defending conservative-leaning districts. That's the fracture: a party that spent a decade rallying its base around identity politics and anti-Trump sentiment now finds that base demanding policies the party's own establishment can't sell to the rest of the country.
The question isn't whether Democratic leadership can rein in its left flank. It almost certainly can't. The question is whether anyone will offer working-class Americans a populist alternative that isn't corporate Republicanism or socialist Democrat — before those become the only choices left.
