Unaffiliated voters are Colorado's largest registration bloc. Under the state's semi-open primary, they receive both major-party ballots and may return one. But the public contest totals do not disclose whether each vote came from an unaffiliated voter or a registered partisan. Any district-level Democratic-versus-Republican split therefore combines several things: party registration, unaffiliated participation, candidate competition, undervotes, and turnout.
That limit changes what the three-cycle comparison can prove. It cannot tell us which ballot Colorado's unaffiliated voters chose. It can tell us that the Democratic share of all two-party U.S. House primary votes rose in every district against both the 2022 and 2024 baselines.
The Democratic share rose against both baselines
The most comparable district-level measure is the U.S. House primary — the one office present on every partisan ballot in a congressional district. Count the votes cast in each party's House primary, take the Democratic share of the two-party total, and compare the June 2026 result with the same measure in 2022 and 2024 on Colorado's current eight-district map.
Every district was more Democratic in 2026 than in either earlier year.
| District | 2022 | 2024 | 2026 certified | vs 2022 | vs 2024 |
|---|---|---|---|---|---|
| CO-01 — Denver | 84.1% | 87.3% | 91.3% | +7.2 | +4.0 |
| CO-02 — Boulder, Fort Collins | 68.0% | 74.7% | 78.5% | +10.5 | +3.8 |
| CO-03 — Western Slope, Pueblo | 31.7% | 36.9% | 48.1% | +16.4 | +11.2 |
| CO-04 — Eastern Plains, Douglas | 25.8% | 28.7% | 44.1% | +18.3 | +15.4 |
| CO-05 — Colorado Springs | 31.4% | 32.1% | 49.3% | +17.9 | +17.2 |
| CO-06 — Aurora | 56.2% | 64.4% | 71.0% | +14.8 | +6.6 |
| CO-07 — Jefferson County | 44.1% | 60.6% | 65.9% | +21.8 | +5.3 |
| CO-08 — Adams & Weld | 40.0% | 43.7% | 62.6% | +22.6 | +18.9 |
Statewide, the Democratic share of the combined two-party House-primary vote moved from 45.5% in 2022 to 50.5% in 2024 and 63.9% in 2026. The certified 2026 House contests contained 1,277,609 votes. The Secretary of State reported 1,444,304 ballots cast across the election, a larger denominator that includes ballots with no House vote and other ballot types.
The contested races changed underneath the series. In 2022, the most visible statewide contests were Republican primaries for U.S. Senate and governor while Democratic statewide incumbents ran without opposition. In 2024, neither governor nor U.S. Senate was on the June ballot, and the crowded Republican primary in the 4th was a major draw. In 2026, the marquee statewide contests were Democratic: Attorney General Phil Weiser defeated Senator Michael Bennet for governor, 56.9% to 43.1%, and Senator John Hickenlooper defeated state senator Julie Gonzales, 52.8% to 47.2%.
That changing contest map is a reason for caution, not a way to subtract candidate effects. The broad rise in Democratic House-primary share is a real feature of the returns; the aggregate data cannot say how much came from unaffiliated voters, registered partisans, or the races available on each ballot.
Four Republican-held seats beside the forecast
A primary is not a general election, and this participation measure is not a forecast input unless the model explicitly says so. It is most useful as context beside the four Colorado seats held by Republicans and the current Akashic forecast.
| Seat (GOP incumbent) | 2026 Dem primary share | District lean, 2024 pres. | 2024 U.S. House result | Akashic rating |
|---|---|---|---|---|
| CO-08 — Gabe Evans | 62.6% | Trump +1.8 | Evans +0.7 | Likely D |
| CO-03 — Jeff Hurd | 48.1% | Trump +9.7 | Hurd +5.0 | Tilt D |
| CO-05 — Jeff Crank | 49.3% | Trump +9.1 | Crank +13.8 | Tilt D |
| CO-04 — Lauren Boebert | 44.1% | Trump +18.2 | Boebert +11.6 | Tilt D |
The 8th is the most conventionally competitive seat in the group. Trump carried it by under two points in 2024, and Gabe Evans won the House race by seven-tenths. It also posted the largest increase in Democratic House-primary share against 2022 and one of the largest against 2024. Akashic's July 8 forecast rates it Likely D.
The other three are harder reaches. The current forecast rates each Tilt D, its least-confident Democratic tier, despite Republican presidential margins of roughly nine to eighteen points in 2024. Those ratings are model outputs, not consequences established by this primary table. The primary results add evidence of unusually Democratic participation in 2026; they do not show how those voters will behave in November or whether the environment will persist.
The map voters created
Colorado's eight districts were drawn by the independent commission voters created in 2018. When the commission finished in 2021, it produced four Democratic-held seats, three safely Republican seats, and a new competitive 8th District rather than a map engineered for either party.
The 2026 House-primary shift is visible in all four Republican-held districts, including the swing district and three seats with much stronger Republican general-election baselines. If Democrats win any of them, they will have done so within the voter-created map rather than through a partisan redraw. That is an institutional fact. The primary alone cannot promise the electoral result.
The same caution applies inside the Democratic column. In Denver's 1st District, Melat Kiros defeated Diana DeGette, Colorado's longest-serving House member, by roughly 53% to 40%. A heavily Democratic primary electorate can remove a Democratic incumbent as readily as it can signal general-election engagement. Participation is real; it is not obedience.
The atlas ingested the 2026 party-segmented ballot alongside the 2022 and 2024 baselines in co_primary_2026.json. The article's 2026 House figures were then checked against the Secretary of State's certified statewide abstract.