The City of Denver, Latino civil rights organizations and government watch groups asked a federal judge on Thursday to block the Trump administration from allowing armed federal immigration agents to serve warrants at polling sites.

The lawsuit, filed in federal court in Washington, D.C., asserts that Markwayne Mullin, the homeland security secretary, and David Venturella, the acting head of Immigration and Customs Enforcement, are allowing federal agents to enforce civil immigration laws at polling locations as a matter of policy. The plaintiffs argue that the practice violates federal laws protecting free and fair elections.

“The presence of federal force at the polls interferes with the smooth administration of elections at the local level,” the lawsuit states. “It disrupts voting and makes it more difficult for state and local election officials and law enforcement to do their jobs by making polling places spaces of confrontation.”

The Department of Homeland Security and ICE did not immediately respond to requests for comment.

Speaking to reporters last week in New York, Mullin said that Democrats were fearmongering and that ICE was not patrolling polling places. “The only reason why we would be at polling places is if there is a threat to that polling place,” he said, “or we’re serving a warrant.”

The groups that brought the suit argue such actions violate federal law, which bans military personnel or other “armed” agents from being “at any place where a general or special election is held, unless such force be necessary to repel armed enemies of the United States.”

Their case is the first lawsuit against the administration over such actions.

Civil rights and government watch groups say they have chronicled several encounters at polling sites nationwide since the spring that they said failed to meet that bar. In May, they allege, armed agents “swarmed” the parking lot of an active polling site in San Antonio to detain a person in plain view of voters until the county sheriff ordered them leave.

In June, ICE agents entered a polling site in Syracuse, New York, to interrogate an election volunteer over a social media post that she made five months earlier regarding the fatal ICE shooting of a woman in Minneapolis, according to the lawsuit.

The possibility of federal agents at the ballot box has intensified concerns of Election Day chaos in an already volatile campaign season. Ahead of the 2026 midterms in November, the Trump administration has sought to impose restrictions on mail voting, prompted a congressional redistricting race and escalated efforts to identify and deport noncitizens who registered to vote, even with no evidence of widespread voter fraud.

Fears that the Trump administration might send armed federal agents or troops to polling places or election offices have simmered among Democrats, voting rights groups and immigrant rights networks for months. Trump has long repeated unfounded assertions of electoral fraud and has called for Republican officials to “take over” elections in parts of the country.

Trump administration officials have said there is no plan to deploy armed agents or troops in the upcoming elections. But they have also not ruled out the possibility that armed agents could be present at polling locations or involved in elections.

In the lawsuit filed Thursday, city and county officials in Denver said the area is home to a large immigrant population, making it a likely target for ICE operations during the midterm election.

The presence of armed officers could deter residents from casting votes or dropping off mail-in ballots and could fuel anxiety among election workers and volunteers, they said in the lawsuit. Election officials in Denver have already scheduled training for election workers on how to identify federal agents in plain clothes, document their presence and de-escalate interactions, according to the lawsuit.

In a statement, Mayor Mike Johnston of Denver, a Democrat who has sparred with the Trump administration over its mass deportation efforts, said his city would “fight tooth and nail” to prevent the stationing of ICE agents near polling sites.

“Our right to vote is powerful and enshrined in the U.S. Constitution and U.S. Code,” Paul López, the Denver clerk and recorder, said in a statement.

The groups involved in the lawsuit — Common Cause; the League of United Latin American Citizens, or LULAC; and UnidosUS — said recent ICE activity at polling locations was already chilling voter registration drives, canvassing efforts and civic participation in the electoral process. The organizations have also diverted funding, staff time and ad space away from standard voter mobilization efforts toward establishing rapid-response safety networks, “Vote Safe from ICE” educational materials and de-escalation training.

In a statement, Janet Murguía, the president and CEO of UnidosUS, said sending officers into polling locations was “not immigration enforcement” but “voter suppression, plain and simple.”

Juan Proaño, the CEO of LULAC, called the actions part of the administration’s “attempts to weaken the very institutions it is entrusted to protect.”

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This article originally appeared in The New York Times.

By Jazmine Ulloa/Michelle V. Agins
c. 2026 The New York Times Company