Denver remains Colorado's Democratic bastion and party's key to victory

To win statewide elections in Colorado, Denver is key for the Democratic Party.

Driving the news: Democratic statewide candidates cruised to historic wins thanks to a huge boost in Denver, where all received more than 78% support, a new Axios Denver analysis finds.

• In each race, Denver favored Democrats by roughly 25 percentage points more than the statewide vote.

The same dynamic helped two liberal-minded ballot measures — one increasing affordable housing money and another providing free school meals — win passage.

• Both received over 70% support in Denver, even though they won by much narrower margins statewide, 53% and 57% respectively.

Why it matters: The notion that Denver skews Democratic is not new, but the extent to which it deviates from Colorado as a whole is noteworthy given its outsized power at the state Capitol.

• The numbers also illuminate the Democratic Party's path to victory: Running up the score in Denver is just as important as remaining competitive in swing counties.

What they're saying: "It is a Democratic/Progressive vote bank and there simply isn't a corresponding county on the Republican side," Democratic strategist Curtis Hubbard says.

Context: Denver is the state's second largest county (behind El Paso) and home to 20% of Colorado’s registered Democrats — by far the party's largest stronghold.

• Much-smaller Boulder County — often seen as the state's liberal hub — voted less adamantly for Democrats, we found. Denver's support for the party's candidates exceeded Boulder County by 2-3 percentage points.

The other side: A conservative ballot measure to reduce the state's income tax narrowly won approval in Denver, despite its party allegiances, with 52.8% of the vote.

• The measure, Proposition 121, lost in Boulder County, where it won just 48.2%.

What to watch: Denver (and Boulder County) are seeing population decreases as people move to more affordable neighboring counties or leave the state, demographic data shows. The migration is shifting the political landscape and may affect voter attitudes.

• El Paso County — the state's largest Republican bastion — is the fastest growing in terms of population.