More than a dozen Democratic legislators and several progressive organizations on Tuesday demanded that Republican U.S. Sen. Cory Gardner pledge he won’t vote for Mitch McConnell as Senate GOP leader after the fall election.

The left-leaning Coloradans cited McConnell’s support for business interests and his recent suggestion that local governments should “take the bankruptcy route” in the face of a fiscal crisis brought on by the coronavirus pandemic as reasons they think Gardner should repudiate the Kentucky Republican.

“When you were first elected to the Senate, it was on a pledge to be an independent voice for Coloradans.,” wrote the group in a one-page letter delivered to Gardner’s office. “Now, keeping your word means making a different pledge: that if re-elected, you will not vote for Mitch McConnell as your party’s leader in the Senate.”

A spokesman for Gardner’s campaign declined to comment.

Seeking a second term, Gardner is considered one of the most vulnerable Republican senators on the ballot this year. He’ll face the winner of a June primary between Democrats John Hickenlooper, a former two-term governor, and Andrew Romanoff, a former state House speaker.

McConnell, in his 14th year as Republican leader, ranks as the least popular politician among Colorado voters, according to a poll released Monday that was commissioned by one of the groups that signed the letter asking Gardner to spurn McConnell.

With 53% of registered voters holding an unfavorable opinion of McConnell and just 22% viewing him favorably, McConnell’s negative 31 percentage point net favorability puts him below Republicans in Congress, House Democratic Leader Nancy Pelosi and President Donald Trump, in that order, a Global Strategy Group survey conducted for ProgressNow Colorado found.

Gardner, the same poll found, is viewed favorably by 34% of voters and unfavorably by 46%, for a negative 12 percentage point net favorability. 

The letter’s signers include House Speaker KC Becker of Boulder, state Sen. Brittany Pettersen of Lakewood, state Rep. Kyle Mullica of Thornton and state Rep. Tom Sullivan of Centennial. Other signers are Indivisible Front Range Resistance, ProgressNow Colorado, former state Sen. Polly Baca, and former ambassador Dan Baer, who ran last year in the Democratic primary to challenge Gardner.

Cut the Strings CO, a group formed to draw attention to Gardner’s links to McConnell, was also involved in the letter, and its spokeswoman, Marie Aberger, is among its signers.