Colorado state Sen. Kevin Priola announced on Monday he is switching to the Democratic Party, saying he could not “in good conscience” be silent about Republicans who baselessly cast doubt on the validity of the 2020 election and the existence of climate change.

Priola, a moderate who served four terms in the Colorado House before arriving in the state Senate in 2017, said the GOP has changed since the presidencies of Richard Nixon and Ronald Reagan, and he had hoped the Jan. 6, 2021, attack on the Capitol would cause Republicans to distance themselves from former President Trump.

“Our political affiliations have become too tribal and too much of a litmus test,” he wrote in an open letter posted to his Twitter account.

“I’ve almost been an independent thinker and sometimes buck the conventional wisdom of my party, and I don’t plan to change that,” he added. “I do not believe either party has a monopoly on the truth.”

Democrats previously held 20 of the state Senate’s 35 seats, meaning Priola’s party change won’t affect the control of the chamber and will only further cement Democrats’ majority. 

But Priola said his ideological views hadn’t shifted, and he continues to hold conservative views on issues such as abortion, school choice and gun control. 

“To be clear, I will not be changing the way I vote on legislation,” he wrote. “I just simply will now cast my votes with a D next to my name instead of an R.”

Priola said he no longer wants to be affiliated with the Republican Party after Jan. 6, also commending in his letter Republicans who have broken with Trump’s position on the riots, including former Vice President Pence, Sen. Mitt Romney (Utah) and Reps. Liz Cheney (Wyo.) and Adam Kinzinger (Ill.).

In the wake of the Capitol insurrection, Priola told Colorado Politics that he supported removing Trump from office through the 25th Amendment. He also was the sole Republican to vote with Democrats to call on Congress to pass federal voting rights legislation the same month, Denver7 News reported.

“I cannot continue to be a part of a political party that is okay with a violent attempt to overturn a free and fair election and continues to peddle claims that the 2020 election was stolen,” Priola said.

He also took aim at Republicans’ position on climate change, calling the issue a crisis and an existential threat. Priola noted that Nixon, a Republican, signed legislation as president establishing the Environmental Protection Agency (EPA).

“Today, my Republican colleagues would rather deny the existence of human-caused climate change than take action,” he said. “I increasingly believe this inaction is counter to our responsibility as political leaders.”

Colorado GOP Chairwoman Kristi Burton Brown said in a pair of tweets that Priola has “finally made the move to the party he’s consistently voted with.”

“After lying to his constituents, routinely voting for tax increases, & hurting the working families of his district, he’s now admitted his true affiliation: a pro tax-increase Democrat,” she continued. “It’s clear that Priola has selfishly chosen to make himself the story at the expense of Coloradans he was elected to fight for. He will regret this decision when he is in the minority come January 2023.”

Colorado state Senate President Steve Fenberg (D) celebrated Priola’s decision in a statement, saying the lawmaker chose his constituents over partisan politics.

“Where we’ve had disagreements with Senator Priola in the past, we have always maintained a respectful dialogue,” Fenberg said. “That conversation will continue, only now we will be engaging him as a member of the Democratic Party.”