Colorado’s two Democratic senators will not vote to confirm President Donald Trump’s nominee to a vacancy on the Denver-based federal appeals court.

Trump has selected U.S. District Court Chief Judge Daniel D. Domenico, who he appointed as a federal trial judge in 2019, to fill a vacancy arising out of Colorado on the powerful U.S. Court of Appeals for the 10th Circuit. The court issues binding interpretations of law in federal cases from Colorado and five neighboring states.

In statements provided to Colorado Politics, U.S. Sens. Michael Bennet and John Hickenlooper explained their positions by citing Domenico’s history of decisions and his statements during this week’s Senate Judiciary Committee hearing, in which he declined to acknowledge former President Joe Biden’s victory over Trump in the 2020 election.

“The judge’s record and answers to the Committee, including his refusal to say who won the 2020 election and his immigration rulings, make it clear that he should not be confirmed to the circuit court,” wrote a spokesperson for Hickenlooper’s office. “Senator Hickenlooper will not return a blue slip on the nomination and will not support his nomination should it advance to the full Senate.”

A “blue slip” refers to the tradition in which senators are empowered to block judicial nominees from their home states. Currently, the Senate only honors blue slips for district court nominees.

Bennet, who voted to confirm Domenico to his trial court judgeship in 2019, said he has concerns about Domenico’s self-acknowledged outlier status as the only federal judge in Colorado to side with the government’s expansive view of its immigration detention authority.

“When Judge Domenico last came before the Senate for a nomination to the U.S. District Court, his record was based primarily on his tenure as Colorado’s Solicitor General and his work in private practice,” said Bennet in a statement originally submitted to the judiciary committee. “Today, we have the benefit of more than seven years of judicial rulings and a more complete view of the manner in which he approaches his responsibilities — including Judge Domenico’s recent decision upholding the government’s ability to detain individuals in immigration custody without a bond hearing, a position at odds with every other federal district judge and magistrate judge in Colorado.”

He continued that an appellate judgeship is “fundamentally different from and more consequential than that of a district court judge, and serious questions remain about his interpretations of constitutional and statutory text. Moreover, we are considering Judge Domenico for this new position at a moment when the Trump Administration has spent years undermining the rule of law and eroding the independence of the federal courts. I cannot support his nomination in this context.”

Both senators face challenges in the June 30 Democratic primary election, with Hickenlooper running for a second term in the Senate and Bennet pursuing his party’s nomination to become governor next year.

Domenico is seeking to succeed Judge Timothy M. Tymkovich, a George W. Bush appointee and Domenico’s former boss. If confirmed to the 10th Circuit, Domenico would join two of Trump’s first-term appointees, Judges Allison H. Eid of Colorado and Joel M. Carson III of New Mexico.

The judiciary committee received several letters endorsing Domenico’s nomination. Former Republican Attorney General John Suthers, who hired Domenico to be Colorado’s solicitor general, wrote that he “always believed (Domenico) was best suited for the appellate bench.”

“His allegiance is to the law and he will conduct himself free of partisan influence. He understands the importance of an independent judiciary to our system of government,” Suthers added.

Two former governors, Republican Bill Owens and Democrat Bill Ritter, wrote that Domenico “earned a reputation across the Colorado legal community for his intellectual rigor, fairness, and fidelity to the law. He does not approach cases with an eye toward political outcomes but follows precedent, applies the law as written and respects the proper role of the judiciary in our constitutional system.”

The committee also heard from former law clerks of Tymkovich, Colorado attorneys, six former solicitors general of other states, Domenico’s former law clerks and a former 10th Circuit judge from Utah.

Two progressive organizations, Alliance for Justice and People For the American Way, have also issued position papers opposing Domenico’s confirmation, based in whole or in part on his record.