It was a dire warning, delivered on the biggest stage: Some 278,000 noncitizens were improperly registered to vote in federal elections and were poised to tilt the scales of the election in November, President Donald Trump warned in a primetime address to the nation in July. "The real number is actually much higher," he added.

The president's bold claim set off a series of events that culminated in recent weeks with an unprecedented bid by the federal government to impose itself on state-run elections.

The Trump administration has sued the state of California and threatened other states over the issue of noncitizen voting, a longtime concern of the president and his administration despite experts saying it is already illegal and "vanishingly rare." Federal officials have demanded action after presenting to states what they say are lists of noncitizens who are registered to vote, gathered using a combination of federal immigration data and commercially available state voter registration rolls. But in the final weeks of the campaign, as the administration implores state and local officials, both in and out of court, to investigate those individuals, the lists -- and the grandiose numbers Trump and his allies publicly trumpeted -- appear to be buckling under the scrutiny of state and local election officials. In California, Washington and Nevada -- and beyond -- state and local officials say the lists provided by the Justice Department appear grossly inaccurate and justify the states' reluctance to purge individuals from registration lists so close to the election.

The Trump administration initially accused California of harboring over 190,000 noncitizen voters on its rolls over the summer.

That sum was whittled down to 20,000 by the time the Justice Department filed its lawsuit against the state last week.

It's not clear why the administration reduced the figure so dramatically. But even the smaller figure seems inflated, according to state and local officials.

In court filings, officials in Los Angeles County said a preliminary review of 200 individuals on the list showed that nearly 40% "indicate that they were born in the United States, which is strong evidence of citizenship; and 71.2% of the records have no voting history." Judge David Carter, the federal judge assigned to the case, rejected the Justice Department's push for an emergency intervention based in part on what he called the administration's "unreliability" and "lack of credibility."

Late last week, separate from its litigation against the state, the DOJ sent letters to every California county asking local elections officials to help identify potential voters who may be in the U.S. illegally, according to a letter described to ABC News.

"Within 48 hours, we ask that you commit to working with DOJ and DHS to identify who on the accompanying list is a citizen and who is not," according to the letter sent by Justice Department officials. Since then, county election officials have been sifting through the lists.

According to some county officials, the results so far seem to confirm their skepticism of the Trump administration's claims.

In Butte County, situated just north of the Sacramento Valley, officials received a list of 47 names from federal prosecutors late Friday. The county's top election official, Keaton Denlay, told ABC News that he personally reviewed what he called the Justice Department's "poorly formatted excel spreadsheet with missing and jumbled information."

Denlay found that 32 of the 47 individuals "are not on Butte county's active voter rolls," and another seven "did not have sufficient information for me to match to our voter list with confidence." Officials in Nevada County received a list of just 10 names. Their review "found no evidence of non-citizen voting in the November 3, 2026 Election," an official said. Of the 33 names sent to officials in San Benito County, officials there said, "a preliminary review ... indicated that not all listed individuals were currently registered to vote in San Benito County," without specifying how many. Other county officials contacted by ABC News said they were either still reviewing the list or analyzing their legal obligation to cooperate with the Justice Department.

A Justice Department official told ABC News that, as of Thursday, the DOJ under Trump had charged roughly 200 individuals across the country with either illegal voting or unlawful voter registration-related offenses.

Federal prosecutors in Washington state convened the media on Monday for a press conference where they accused state leaders of knowingly allowing some 400 noncitizens to vote this fall, calling that figure just "the tip of the iceberg."

The top election official in Washington state issued a blistering response on Wednesday, claiming that a preliminary review of the Justice Department's list found a number of U.S. citizens, as well as "several" other individuals who are not registered to vote.

"The information you provided contains several glaring deficiencies," wrote Steve Hobbs, the Washington secretary of state in response the DOJ. "You provide no information about how the information was collected or what sources were used.

Nor do you provide any backup documentation supporting your assertions." Hobbs said this close to an election, the risk of removing individuals from registration lists or sequestering their ballots would risk disenfranchising eligible voters, a sentiment shared by election officials around the country and the judge overseeing the Justice Department's case in California.

"It is almost certain more people named on this list are also United States citizens; those already identified may just be the 'tip of the iceberg' of individuals that would be wrongfully disenfranchised by the actions you request," Hobbs told the DOJ.

In August, federal officials alerted Nevada state leaders, including Nevada Secretary of State Francisco Aguilar, that there could be as many as 15,903 noncitizens registered to vote in the state. The two parties met on a video conference to discuss the figure.

According to a recording of the video conference obtained by ABC News, the meeting was not overtly hostile -- but there appeared to be palpable tension and some awkward exchanges, as Nevada officials seemed deeply skeptical of the claims made by Department of Homeland Security officials.

"So what you're saying is the 15,000 number has not been vetted?" a Nevada official asked, according to the recording. "I probably wouldn't use the sentence, 'It hasn't been vetted,'" a DHS representative responded, adding that each individual has not "had a full manual review."

"So it went from 16,000, and then to the 185, and then down to zero from our perspective," Aguilar said. "There's no trust in that relationship," Aguilar later told ABC News.

"In order to have a working relationship, there has to be trust, and the fact that they continue to tear that trust apart and spread the misinformation and the lies that they are about our elections is wrong." In response to a request by ABC News for comment earlier this month, DHS stood by its work, which it called "a service to Nevada's citizens," and accused Nevada officials of knowingly harboring illegal voters on its lists. "Nevada knows the 185 names they keep waving around were never the full list of illegal voters," a Homeland Security spokesperson said in an email.

"They were only the files [that immigration officials] had finished reviewing at the moment of the call. Since then, [immigration officials] have manually confirmed about 2,000 more aliens from the same list." They concluded: "The review is just beginning."