1-minute voter guide: Democratic U.S. Senate race

State of play: Incumbent U.S. Sen. John Hickenlooper, the former Denver mayor and governor, is facing a primary challenge from state Sen. Julie Gonzales, a progressive who argues Democrats need a more confrontational response to President Trump and a sharper break from establishment politics.

• Hickenlooper, 74, has pledged that 2026 is his final political campaign. He's running on his experience working across party lines and labeling himself a "fighter" against Trump.
• Gonzales, 43, is campaigning for generational change and rejects the idea of "incrementalist" politics.

Zoom in: The two candidates differ widely on policy, the Colorado Sun reports.

• In health care, Hickenlooper supports a publicly funded option for health insurance while Gonzales wants to go further with a "Medicare for All" approach and the abolition of private health insurance.
• He opposes a ban on hydraulic fracturing in oil and gas drilling, while Gonzales would support one.

Yes, but: Both support dismantling the U.S. Immigration and Enforcement agency.

The intrigue: Hickenlooper is refusing to appear on stage with Gonzales for a debate, and he's skipping many campaign forums that she is attending.

• Meanwhile, Gonzales has energized progressive activists who put her name at the top of the ballot.

The bottom line: It will serve as a test of whether the party still favors Hickenlooper's pragmatic, coalition-building style or wants Gonzales' more ideological and activist-driven vision.