Denver filed a federal lawsuit Thursday against the Department of Homeland Security, seeking to block a policy the city says would send armed Immigration and Customs Enforcement agents to polling places during November's midterm elections.

The suit, filed in U.S. District Court for the District of Columbia and joined by a coalition of civil rights and immigrant-rights groups, names DHS, Secretary Markwayne Mullin, ICE and Acting ICE Director David Venturella as defendants, according to Denverite.

A Civil War-Era Law at the Center

The complaint argues the policy — outlined publicly by Secretary Mullin, who said DHS was "prepared" to conduct immigration enforcement at polling locations — would violate a federal law barring armed officials from being stationed to "keep the peace" at polls during federal elections, a protection with roots in Reconstruction-era voting rights statutes, according to The Hill.

"[The policy] places voters in fear that they will be confronted by armed federal immigration enforcement officers if they choose to cast a ballot," the complaint states.

ARMED AGENTS AT THE BALLOT BOX?

Denver's suit follows a separate lawsuit from the voting-rights group Common Cause accusing federal agencies of violating First Amendment and privacy rights by intimidating election observers during ICE raids — described in reporting as the largest observer-intimidation lawsuit filed to date, according to UPI.

DHS has not publicly responded to the Denver lawsuit.

What's Next

A hearing date has not yet been set. The case adds to a growing pile of pre-midterm legal fights over ballot access and federal enforcement policy heading into November.