Congress Votes to Block U.S.P.S. Changes

“Don’t pay any attention to what the president is saying because it’s all designed to suppress the vote,” Speaker Nancy Pelosi of California said before the vote.

Postal leaders have been warning for months that the sharp decline in mail caused by the pandemic could jeopardize the solvency of an agency that has struggled to turn a profit. But Mr. DeJoy, a Trump donor and former logistics executive, introduced measures to cut down on transportation costs and overtime this summer, leading to substantial delivery delays of vital items like medicines, checks and even chicks. Democrats and postal unions began to caution that the Trump administration may be moving to destabilize the Postal Service during an election year and aid its private competitors because of the president’s animus against mail-in voting.

In his tweets on Saturday, he said the Postal Service did not need the money, despite its outstanding request to Congress for the funds, and repeated false claims that voting by mail is fraudulent.

He accused Democrats of backing a universal vote-by-mail “scam” in “violation of everything that our Country stands for.”

Voting by mail is neither new, a scam, nor at risk of widespread fraud, as Mr. Trump insists. Millions of Americans in conservative and liberal states alike cast their ballots through the Postal Service in 2016 and 2018. Mr. Trump plans to do so this year, but makes a distinction between absentee voting through the mail and programs overseen by Republicans and Democrats that proactively send ballots to all voters.

Adding to some lawmakers’ worries, Mr. DeJoy’s changes coincided with the long-planned removal of hundreds of blue postal collection boxes across the country and the decommissioning of mail-sorting machines, part of a regular practice to adjust to the steady decline of mail.

Many Republican lawmakers have joined Democrats in voicing concern over the slowdowns and demanding assurances from Mr. DeJoy and others that the Postal Service will be able to carry out the vote-by-mail initiatives.