Minnesota Gov. Tim Walz, the Democratic nominee for vice president, accused his Republican counterpart, U.S. Sen. JD Vance, on Tuesday of working to “demonize” immigrants by fabricating a widely debunked rumor that Haitian migrants in Springfield, Ohio have eaten residents’ pets.

In the media room at CBS studios, laughter erupted as Vance continued talking for several seconds, unaware his microphone had been muted.