The group of Trump campaign officials came carrying cellphone cameras and a determination to help the president’s re-election efforts in Philadelphia. But they were asked to leave the city’s newly opened satellite election offices on Tuesday after being told local election laws did not permit them to monitor voters coming to request and complete absentee ballots.

On social media and right-wing news sites and in the presidential debate on Tuesday night, President Trump and his campaign quickly suggested nefarious intent in the actions of local election officials, with the president claiming during the debate that “bad things happen in Philadelphia” and urging his supporters everywhere to “go into the polls and watch very carefully.”

The baseless descriptions of the voting process in Philadelphia were the latest broad-brush attempt by the Trump campaign to undermine confidence in this year’s election, a message delivered with an ominous edge at the debate when he advised an extremist group, the Proud Boys, to “stand back and stand by” in his remarks about the election.