Congressional Democrats are calling on Postmaster General Louis DeJoy to protect the country’s mail from future delivery delays and raising questions about his leadership, urging President Joe Biden to fill vacancies on the US Postal Service’s Board of Governors so that the board can “seriously consider” whether the Trump administration appointee “is suitable to continue in his role.”

In two separate letters sent to DeJoy and Biden this week, scores of Democratic lawmakers raised a number of complaints about the postmaster general, who has told those close to him he wants to stay in his role under the new President, two sources told CNN earlier this month, despite his troubled tenure at the helm of the USPS and his background as a supporter and donor to former President Donald Trump.

Together, the two letters underscore the party’s deep frustration with DeJoy, whose decisions in the run-up to the 2020 election were criticized by Democrats for hamstringing USPS at a time when many Americans were relying on it to cast mail-in ballots. Federal judges across the country issued unprecedented decisions to temporarily block DeJoy’s changes from being implemented ahead of the election.

“It is your duty, first and foremost, to protect service and ensure timely mail delivery for every person in this nation,” 34 Democratic senators wrote to DeJoy, acknowledging that USPS “fulfilled its duties during the 2020 general election and executed extraordinary measures to prioritize timely delivery of election mail” but that concerns remain about delivery delays.

Delays from “peak season” have persisted “despite the tireless effort of postal workers,” the senators wrote, which they said is impacting the delivery of important mail, like prescription drugs and rent payments.

The senators called Covid-19-related delays, as well as the high volume of mail and reduced airlift and trucking capacity, “credible explanations,” but added, “the fact remains that USPS leadership had a responsibility to prepare for these expected challenges. We question whether management made adequate preparations including sufficient temporary hiring and logistical planning.”

“We also question whether your decisions and directives continue to hinder mail delivery,” the senators posed to DeJoy, noting that he has announced that additional changes will be coming soon.

“We demand that you not make additional changes that will harm service for the American people. In addition, we urge you to be fully transparent with the public about Postal Service operations and the reasons they are still facing delays,” the senators wrote, listing a series of questions about service for DeJoy to answer by February 26.

The letter was sent after a group of 80 House Democrats sent a separate letter to Biden on Tuesday in which they urged him to fill vacancies on the board of governors so new members can “seriously consider” DeJoy’s future.

While the House members do not call for the Biden administration to completely wipe out the board, which would include the Trump appointees still there, they ask that the President “submit nominations for the three vacant positions” so that the board can “function in a more nonpartisan, effective manner.”

“We do not doubt that the Postal Service requires some thoughtful reforms in order to continue to provide excellent service to the American people in the years to come; however, there is a plethora of evidence that Postmaster General DeJoy is not equipped to meet the rigors of these challenges,” the lawmakers wrote.

“Filling the vacant seats on the Postal Service’s Board of Governors with strong, passionate advocates for the institution will allow it to function in a nonpartisan manner, and will allow the Board to seriously consider whether the current Postmaster General is suitable to continue in his role.”

The letter also took direct aim at DeJoy, with the House Democrats noting that he was a “Republican Party mega donor, who had no experience working for the Postal Service prior to his appointment.”

“Since Mr. DeJoy assumed office, he has, under the guise of enacting needed reforms, rapidly transformed the Postal Service to the detriment of Americans,” they said. “Critically, the on-time delivery of flat mail has plunged drastically.”

Getting rid of DeJoy is not a clean-cut process. The President does not have the power to remove the Postmaster General. Only the Postal Service Board of Governors  which is comprised of members nominated by the President and confirmed in the Senate  has the power to do so, and DeJoy continues to have the support of the

Trump-appointed boar, Although, Biden has the power to nominate members of the board and to send them to the Senate now led by Democrats for confirmation. Some lawmakers want Biden to go beyond filling empty seats, and take drastic action by firing the entire board.