Democrats are pinning their hopes of flipping the Senate on Graham Platner, who has made his working-class persona key to his campaign. His background defies easy categorization.

He directed nearly 1,000 comedic commercials, including a much-quoted spot for Wendy’s and one for FedEx featuring a manic speed talker.

It is not clear when another trial would take place. But both prosecutors and defense lawyers said they would be forced to revise their legal strategies.