Coloradans head to the polls today to decide which candidates the two major parties will nominate for the November ballot. Nearly all of the most competitive primaries are in the Republican primary this year, since Democratic incumbents are seeking reelection without opposition in their primaries. Both parties’ ballots feature hotly contested congressional and legislative primaries in parts of the state.

The Colorado Politics, in partnership with The Denver Gazette and The Colorado Springs Gazette, will provide updates throughout the day. On Twitter, follow us at @colo_politics, @DenverGazette and @csgazette.

LATEST: US Reps. Diana DeGette, Ken Buck cruise to renomination in Colorado congressional primaries

U.S. Rep. Diana DeGette, a Denver Democrat, and U.S. Rep. Ken Buck, a Windsor Republican, sailed to victories Tuesday over first-time candidates in their respective primaries in Colorado. 

Erik Aadland wins GOP primary in Colorado’s 7th CD, will face Pettersen in November

Former energy industry executive Erik Aadland took an early lead  and kept it Tuesday in the Republican primary for the Colorado congressional seat held by retiring Democratic U.S. Rep. Ed Perlmutter.

Incumbent US Rep. Doug Lamborn beats challenger Dave Williams, two others in 5th CD Republican primary

U.S. Rep. Doug Lamborn won the Republican nomination for a ninth term representing the 5th Congressional District on Tuesday, according to early, unofficial primary returns.

US Rep. Doug Lamborn beats challenger Dave Williams, two others in 5th CD GOP primary

Heidi Ganahl defeats Greg Lopez in Colorado’s Republican gubernatorial primary

University of Colorado Regent Heidi Ganahl took the lead early over former Parker Mayor Greg Lopez and kept it in the state’s Republican gubernatorial primary on Tuesday.

Heidi Ganahl defeats Greg Lopez in Colorado's Republican gubernatorial primary

Joe O’Dea rolls over Ron Hanks in GOP primary for Colorado’s US Senate seat

Republican business owner Joe O’Dea jumped out to an early lead Tuesday night over state Rep. Ron Hanks, R-Cañon City, in the Colorado primary to decide who takes on Democratic U.S. Sen. Michael Bennet.

Joe O'Dea rolls over Ron Hanks in GOP primary for Colorado's US Senate seat

Watch O’Dea’s victory speech:

AP calls gov, SoS, Senate races for traditional Republicans

The Associated Press has declared Heidi Ganahl, Joe O’Dea and Pam Anderson – widely regarded as traditional Republicans – winners over their Republican rivals in their respective races.

Their victory comes amid heavy spending by Democrats in what former Colorado Gov. Bill Owens denounced as a “disingenuous” attempt to influence the state’s Republican primaries for governor and U.S. Senate by encouraging GOP voters to nominate candidates he describes as “second tier.”

A pair of TV ads that hit the air described Republicans Ron Hanks and Greg Lopez — primary candidates for senator and governor, respectively — as “too conservative for Colorado,” noting that both support banning abortion and agree with former President Donald Trump that the 2020 election was stolen, among other positions.

Barb Kirkmeyer takes wide lead in GOP primary in Colorado’s new 8th CD

State Sen. Barbara Kirkmeyer took the lead in early returns in the Republican primary in Colorado’s new congressional district.

Barb Kirkmeyer wins four-way GOP primary in Colorado's new 8th CD

AP declares Lauren Boebert winner in GOP primary

Watch Boebert’s victory speech:

Heidi Ganahl holds lead over Greg Lopez in governor’s race

Heidi Ganahl, a University of Colorado regent, holds the early lead over rival Greg Lopez in the Republican race for governor. Ganahl has cornered 56% of the vote, while Lopez trails with 44%, the unofficial early tally shows.

Some 255,000 votes have been counted so far.

LATEST: Pam Anderson is ahead of the pack 

Pam Anderson has so far received the plurality in the GOP race for Secretary of State, with Mesa County County Clerk and Recorder Tina Peters trailing in third place. 

Anderson secured 45%, compared to Peters’ 25% and Mike O’Donnell’s 29%, with roughly 278,000 votes counted so far.

More from KUSA:

Joe O’Dea leads Ron Hanks, Lauren Boebert holds early lead over Don Coram

Businessman Joe O’Dea is leading state Rep. Ron Hanks in the Republican race for the U.S. Senate, 58% to 42%, with 167,000 votes counted so far.

Meanwhile, U.S. Rep. Lauren Boebert has surged ahead in the early count, 63% to 37%, in the GOP primary in the 3rd Congressional District with roughly 31,000 votes counted so far. 

Katie March has very slight lead over Elisabeth Epps in Denver-based House district

Former legislative aide Katie March has a very slight lead over criminal justice activist Elisabeth Epps, but the race is tight, the early, unofficially tally shows. 

The two are separated by fewer than 350 votes, with a little over 10,000 votes counted so far.  

Ballot return count nears 1 million

According to the Colorado Secretary of State’s Office, 972,188 ballots have been returned as of 3:30 p.m.

The returns also followed the same trend in the last few days, with Republicans returning more and unaffiliated favoring the GOP ballot. 

The latest tally shows Republicans have returned more than 76,000 ballots, and the unaffiliated have picked up about 37,000 more GOP ballots. 

Outside spending pours millions into legislative races 

Outside groups have spent at least $2.87 million as of June 25 – nearly $1 million of that just in the last two weeks. Read the full story below.   

Unaffiliated pick up more GOP ballots with 830,000 ballots returned as of Tuesday morning 

Roughly 830,000 ballots had been returned as of this morning, with Republicans, who have robust primaries up and down the ticket, returning nearly 52,000 more ballots than Democrats, according to the latest tally from the Secretary of State’s Office.

The same pattern holds true for the unaffiliated, the majority of whom have chosen to vote in the Republican primaries.

The tally shows unaffiliated voters picked up more Republican ballots (123,466) over Democratic ballots (91,115), a 12 percentage point gap.

Secretary of State’s Office says no major problems at polls this morning

The Secretary of State’s Office has not received any reports of voting-related problems at polling centers this morning so far, a department spokesperson told Colorado Politics.  

Watch: KUSA coverage of primary election