An hour into his rally Thursday night in a Pittsburgh suburb, President Trump slammed states that have expanded mail-in voting, a familiar target for his reelection campaign. "These mail-in ballots are a disgrace, and they know it," he scoffed. But Trump isn't alone in trying to undermine faith in absentee ballots. U.S. officials say a Russian disinformation campaign is pushing the same disruptive message to Americans four years after the Kremlin sought to help Trump win the White House.

A Homeland Security intelligence bulletin issued hours before Trump spoke in Latrobe, Pa., warned that a Moscow-backed operation involving state media and proxy websites had "denigrated vote-by-mail processes, alleging they lack transparency and procedural oversight, creating vast opportunities for voter fraud."

U.S. officials say Russia's operation includes false allegations that Democratic presidential nominee Joe Biden's health is failing and that he acted improperly in Ukraine when he served was vice president. Trump has made the same allegations.

The overlap in messaging between Trump's rhetoric and Russian disinformation in some ways echoes the symbiotic relationship between the president's first White House bid and Russian intelligence services in the 2016 election.