U.S. Rep. Ken Buck declared early Monday morning that he is running for a fifth term in Congress, laying to rest speculation the Colorado Republican sparked over the weekend when he took to social media to tease an impending announcement.

Buck, who stepped down last month after serving one term as chairman of the Colorado Republican Party, takes the fight to the Democrats in a campaign video released Monday.

“President Biden and his liberal allies are trying to take away our God-given rights,” Buck says in the video as photos of Vice President Kamala Harris, Massachusetts Sen. Elizabeth Warren and House Speaker Nancy Pelosi flash on screen.

‘”Their tax-and-spend policies will create more big government and less freedom for Americans. The liberals want to dictate which doctor we can see, which gun we can own and which kind of car we can buy. My name Is Ken Buck, and I’m here to put a stop to this. The American experiment runs on freedom, and I plan on keeping it that way.”

Buck, a former Weld County district attorney, added in a statement also released Monday: “I will fight back and do everything in my power to protect what makes America the greatest country in the world. I promise you that I won’t back down from the corrupt liberals in the swamp and their toxic cancel culture.”

Although Buck made clear in January that he wasn’t going to challenge Democratic U.S. Sen. Michael Bennet next year — in what would have been his third run for the seat since 2010 — a Republican blogger suggested Buck was hinting at a Senate bid or possibly planned to launch a campaign against Gov. Jared Polis, setting off an unexpected chain of dominos.

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More than one GOP strategist told Colorado Politics that their best guess was that Buck could be throwing his hat in the ring for Colorado attorney general, an office he considered seeking ahead of the 2018 election before deciding to run for another term representing the heavily Republican 4th Congressional District.

The Colorado GOP has yet to field challengers to Bennet or Democratic Attorney General Phil Weiser, who are both running for re-election next year.

As it’s currently configured, the 4th CD includes Weld County and much of Douglas County, two GOP strongholds, as well as the Eastern Plains. Under its 2020 boundaries, the district voted for Donald Trump by nearly 16 percentage points, the widest margin of any congressional district in Colorado, which voted as a whole for Joe Biden by 13 percentage points.

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According to the Cook Political Report, the current district has a Partisan Voter Index score of R+12, meaning it votes about 12 percentage points more Republican than the nation as a whole, though that will change before the next election.

The seat’s 2022 boundaries are unknown, pending action by an independent redistricting commission, which is awaiting final census figures before it can begin drawing final maps.

Democrat Isaac “Ike” McCorkle , who lost to Buck last year by 24 percentage points, is running in the 4th CD again next year, but Buck enters the race with a campaign cash advantage.

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According to finance reports filed last week, Buck raised $150,000 in the year’s first quarter and finished the period with about $375,000 in the bank. McCorkle reported raising about $18,000 and had $161,000 on hand, along with about $5,000 in debt.

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