Democrats are not letting Trump’s attacks on the USPS go without a fight.

It took just a few days for Democratic leaders in Congress and at the state level to start investigating changes at the United States Postal Service (USPS) that could slow down mail delivery and suppress millions of votes in the upcoming election.

Many states are encouraging mail-in or absentee ballots for the presidential election as a safer alternative than voting in person during the coronavirus pandemic. But that system relies heavily on the nation’s postal service, which President Donald Trump has attacked, without evidence, for weeks. On top of this, Postmaster General Louis DeJoy, a major Trump donor, has made operational changes that have, perhaps purposefully, slowed down mail delivery ahead of the election.

After protests this weekend at DeJoy’s houses in Washington, D.C., and North Carolina, House Speaker Nancy Pelosi called on the House to return in the middle of August recess to vote on a bill that would stop USPS from making any changes until after the election. Democrats will vote on the bill as early as August 22. 

“Postmaster General Louis DeJoy, one of the top Trump mega-donors, has proven a complicit crony as he continues to push forward sweeping new operational changes that degrade postal service, delay the mail, and – according to the Postal Service itself – threaten to deny the ability of eligible Americans to cast their votes through the mail in the upcoming elections in a timely fashion,” Pelosi wrote in a letter to her colleagues.

Democratic presidential candidate Joe Biden is also building a plan to fight back against the attacks on the post office. In an interview with the Washington Post, election lawyer and Biden campaign senior adviser Robert Bauer said Trump’s goal is two-fold: keep ballots from arriving in time to be counted and dissuade people from voting at all with constant attacks and misinformation on the process. To fight this, the campaign says it plans “massive expenditures” to educate voters on mail-in ballots and the importance of voting early.

Rep. Carolyn Maloney (D-NY) also sent a letter to USPS officials this weekend, demanding that DeJoy and Robert Duncan, the chairman of the USPS Board of Governors, appear at House Oversight committee hearing as early as next week. The hearing was originally scheduled for September.  

Some members of Congress went further, pointing to potential criminal behavior from DeJoy and the Board of Governors. Reps. Ted Lieu (D-CA) and Hakeem Jeffries (D-NY) sent a letter to the Federal Bureau of Investigations, urging them to look into whether DeJoy and the Board of Governors committed any crimes related to delays within the Postal Service.

“Multiple media investigations show that Postmaster DeJoy and the Board of Governors have retarded the passage of mail. If their intent in doing so was to affect mail-in balloting or was motivated by personal financial reasons, then they likely committed crimes,” Lieu and Jeffries wrote in their letter. 

It’s not just Congress that is working to fix USPS, as state attorneys general also consider legal action. Virginia Attorney General Mark Herring’s staff told CBS News that they have spoken with several other state offices about potential legal action. 

“My colleagues and I are working as we speak to determine what Trump and DeJoy are doing, whether they have already violated or are likely to violate any laws, and what tools we have at our disposal to put a stop to President Trump’s ongoing attack on our postal service and our democracy,” Herring said in a statement to CBS News.

And several individuals, including candidates for public office, sued Trump DeJoy and the USPS in New York on Monday to ensure adequate funding for postal operations.

The lawsuit was filed in Manhattan federal court as multiple lawsuits were threatened across the country as a response to comments the president recently made and actions taken by DeJoy to change operations at post offices nationwide.