A Democratic primary that’s heated up at the last minute in Colorado -- a crucial Senate race that could determine which party controls the chamber next year -- is in the national spotlight on Tuesday as three states hold primaries.

It's also decision day in Utah as former Gov. Jon Huntsman – who stepped down as the state’s governor nearly a dozen years ago to serve as ambassador to China under President Obama – is making a bid for his old job.

And Oklahoma joins Colorado and Utah in holding primaries on the last day of June.

HICKENLOOPER APOLOGIES FOR PAST 'SLAVE SHIP' COMMENT

But the race grabbing the most attention the Democratic Senate primary in Colorado, where some unforced errors by former Gov. John Hickenlooper in recent weeks have made the contest competitive.

Coaxed by national Democrats, the former two-term Denver mayor and two-term governor jumped into a crowded Senate primary field last summer after ending an unsuccessful bid for the Democratic presidential nomination.

The one-time geologist turned brewpub owner enjoyed large campaign cash and name recognition advantages over primary rivals but suffered slip-ups the past couple of months which have somewhat dampened hopes by Democrats that he will oust embattled Republican Sen. Corey Gardner in November’s general election.

Hickenlooper was found in contempt by the state’s independent ethics commission for ignoring a subpoena to appear at a hearing. He testified following plenty of negative media coverage – but was fined $2,750 for two ethics violations.

Over the past month – amid nationwide protests over police brutality against minorities and the bigger issue of systemic racism sparked by George Floyd’s death – Hickenlooper was forced to apologize twice for comments considered insensitive and dismissive to African Americans.

The slip-ups have allowed his much more progressive rival – former state House Speaker Andrew Romanoff – to make the contest closer than expected. And national Democrats worry that a weakened Hickenlooper has given ammunition to Gardner and the GOP to use in the general election – in a race party leaders view as a must win as they hope to regain control of the chamber from the GOP.

WATCH CORY GARNDER ON FOX AND FRIENDS

“Hickenlooper has had a very bad stretch. But he still remains the favorite in the primary,” noted Jessica Taylor of the Cook Report, a leading nonpartisan political handicapper.

But she highlighted that “Hickenlooper certainly has not done a lot lately to inspire confidence.”

On Monday, the day before ballots were due in the all-vote-by-mail primary, Hickenlooper touted a Colorado Supreme Court ruling which unanimously upheld the state’s ban on large-capacity gun magazines.

“In Colorado, we took on the NRA and won to pass life-saving gun safety measures. I'm thrilled that the Colorado Supreme Court has upheld this crucial legislation—now let's bring these same results to Washington,” he tweeted.

THE LATEST FROM FOX NEWS ON THE 2020 PRESIDENTIAL ELECTION

Romanoff in the closing days has touted his “bold, progressive agenda that matches the urgency of this moment,” including his support for the Green New Deal and Medicare-for-all.

In Utah, Huntsman appears to be tied with Lt. Gov. Spencer Cox in the race for the Republican gubernatorial nomination.

The winner of the GOP multi-candidate primary will be considered the favorite in November to win election as governor in a state heavily dominated by Republicans.

Cox has the endorsement of term-limited Republican Gov. Gary Herbert, who took over after Huntsman stepped down nearly a dozen years ago. But Huntsman has enjoyed the cash advantage in the race – as well as much larger name recognition – thanks to his tenure as ambassador to China under Obama, ambassador to Russia under President Trump, and his unsuccessful 2012 campaign for the Republican presidential nomination.

In Oklahoma, a ballot initiative that would expand the state’s Medicaid health insurance program is grabbing national attention. The state is one of only 14 across the country that has not expanded Medicaid under the 10-year-old Affordable Care Act, known as ObamaCare.