Progressives scored wins in Colorado’s Democratic midterm primary elections, with democratic socialist Melat Kiros ousting 15-term Representative Diana DeGette (D-CO) in Denver and state AG Phil Weiser defeating moderate Senator Michael Bennet (D-CO) in the gubernatorial primary. Manny Runnel, a progressive state rep, also defeated moderate Shannon Bird in Colorado’s tightest swing district. However, Senator John Hickenlooper (D-CO) held off a progressive challenger in the Senate primary.
- There are concerns amongst the Democratic establishment that the shift to the left, part of a broader debate on the post-Biden direction of the party, could impact Democrats’ chances of flipping the Senate in November, with a recent NYT/Siena College survey in Maine appearing to support Senate Minority Leader Chuck Schumer’s (D-NY) argument that moderate candidates could better appeal to the median voter.
- The Times notes “many voters” said progressive Maine nominee Graham Platner, a political novice facing allegations of personal misconduct, “lacks the background to be an effective senator.”
- The next tests for the left are the Michigan primaries on August 4 and the Wisconsin primaries on August 11, both swing states where left-wing populists are challenging moderates in statewide races. The Michigan Senate primary will be closely followed, as it is one of the “core four” races that Democrats must win to flip the upper chamber.
- While Democrats are still slightly favoured to sweep Congress, a Democratic House/Republican Senate has firmed in recent weeks, with Republican prospects in the Senate improving, per Polymarket.
Figure 1: Balance of Power: 2026 Midterms

Source: Polymarket