Democrats sued President Donald Trump and the US Justice Department over what they say is a coordinated effort to erode confidence in the upcoming midterm elections, including by demanding that states like California and Nevada set aside ballots of suspected non-citizens.

Recent demands by the Trump administration that states segregate tens of thousands of mail-in ballots until voters’ citizenship status can be verified are based on “shoddy” federal data that’s often inaccurate, according to a complaint filed Tuesday in Washington by groups including the Democratic Senate and House campaign committees.

The suit seeks a court order finding that the administration’s “demands and threats” related to the purported lists of non-citizen voters violate the separation of powers and trample the right of states to oversee elections. The groups also want a judge to bar the administration from continuing the effort.

“For over a decade now, President Donald J. Trump has bombarded the American people with lies and misinformation about American elections and voter fraud,” the groups said in the complaint. “While these lies have been debunked at every turn, that has never deterred the president from employing them as a pretext to seize control over elections, even as courts overwhelmingly reject that effort.”Neither the White House nor the US Justice Department immediately returned messages seeking comment.

The Democratic groups said the weakness of the administration’s data was exposed in Nevada, when the Department of Homeland Security “insisted” it had found nearly 16,000 noncitizens on the rolls and then quickly reduced that claim to just 185 voters.

The government ultimately “failed to substantiate even that narrower assertion after Nevada officials indicated that every single one of those voters appeared to be citizens,” the plaintiffs, which also include the Nevada State Democratic Party, said in the complaint.

The Justice Department last week sued California for “refusing” to join its effort to remove suspected non-citizens from the state’s voter rolls. That failure, the DOJ argues, is undermining the US government’s ability to enforce a federal law against non-citizens voting. The administration has asked for a court order requiring California to set aside the disputed 20,000 mail-in ballots until the individuals’ citizenship status can be confirmed.

California earlier on Tuesday asked a judge to reject the administration’s request, saying it was interfering with California laws that already bar illegal voting.

The Democrats’ new suit comes a day after after federal agents across California arrested 11 non-citizens who were charged with crimes including fraudulently registering to vote in US elections, part of a dragnet that the government says bolsters its lawsuit against the most populous state. More than a dozen others were charged but not yet arrested.

According to the DOJ’s complaint against California, a federal agent offered state officials an encrypted thumb drive containing the list of suspected non-citizens who were registered to vote in the state. The officials “rejected” the offer, the DOJ said in its lawsuit, demonstrating “a total lack of commitment to work with the federal government to protect the integrity of our elections.”Trump has been pursuing extraordinary legal tactics to assert greater federal control over US elections, testing the boundaries of Washington’s power over how Americans vote as his Republican Party seeks to keep its majority in Congress in next month’s midterm elections.

While the Constitution largely puts states in charge of elections, Trump has sought to reach into virtually every corner of the voting process as he boosts baseless accusations of widespread voter fraud for his loss in the 2020 election. A prime example is Trump’s push to curb mail-in voting, which has been used by tens of millions of Americans including the president.

The case is DSCC et al v. Trump et al, 26-cv-3674, US District Court, District of Columbia.