“If voters believe Trump did something wrong and just got off on partisan grounds, that can become a real hurdle for him,” said Neera Tanden, president of the influential liberal think tank Center For American Progress.

She said Democratic nominee Al Gore was hurt in 2000 by the fact that President Bill Clinton suffered no punishment for his sexual relationship with Monica Lewinsky, which led to impeachment and his acquittal in 1999.

“The Gore campaign faced hurdles from the fact that Bill Clinton basically got off unscathed,” Tanden said. “A majority never wanted him removed from office. But … the fact that he faced no punishment at all didn’t sit well with the public, either.”