There's growing concern that Trump may deploy the National Guard ahead of elections

National Guard members walk along the Lincoln Memorial at sunrise on the National Mall, with the Washington Monument and the U.S. Capitol dome in the distance, in Washington, D.C., on July 23. Kent Nishimura/AFP via Getty Images hide caption

With Election Day less than 50 days away, a growing number of Democratic lawmakers, retired military leaders and civil society organizations are seeking assurance from members of the Trump administration that the U.S. military will not be deployed to or around polling places — while also preparing for such a move to occur.

Having armed federal agents — like the FBI or Immigration and Customs Enforcement — or military troops near the polls is clearly barred by federal law, but President Trump and several other key officials have recently sidestepped direct lines of questioning around the issue.

Some have even suggested that such a presence might be necessary to ensure trust in the vote, a claim that voting officials across the United States deny. Those voting officials say they plan on administering the midterm elections as usual and have been working hard to assure voters that plans are in place if armed federal officials do show up.

The concern over federal interference at the polls has led to a wave of unprecedented action by civil rights groups, unions and political organizations, including multiple lawsuits , Freedom of Information Act requests and public service announcements to voters about what to watch for on Election Day. And many are specifically ringing alarm bells over the possible involvement of the U.S. military, particularly the National Guard.

Trump's extraordinary use of the National Guard on U.S. soil has already upended democratic norms in the U.S. and unnerved civil rights groups. And experts say the U.S. Supreme Court's recent rejection of Trump's executive order attempting to limit mail voting has backed him into a corner.

"Quite frankly, as this president's options are dwindling, the idea that he might use the military becomes even more of our concern," says retired Air Force military lawyer Maj. Gen. Steven Lepper.

Lepper is part of the Former Judge Advocates Working Group, made up of several dozen retired military lawyers. The group has been tracking the president's executive orders and military deployments and has written several reports to Congress about its worries.