They took a dump on the seat of American democracy — literally.

Some of the unhinged pro-Trump rioters who stormed the U.S. Capitol on Wednesday defecated inside the historic building and “tracked” their feces in several hallways, the Daily News has learned.

A source close to Sen. Chuck Schumer said staffers to the New York Democrat found out about the fecal fiasco on Thursday.

The vile attackers, whose violent invasion of the Capitol left five people dead, apparently went No. 2 in a bathroom and then smeared their extremist excrement around the building, leaving behind brownish “foot-prints,” the source said.

“It looked like they tracked it around,” said the person.