Howard Dean
The 2004 Presidential campaign ended with the Democratic party nearly gaining a chance at contesting Republican incumbent George W. Bush. However, Vermont governor Howard Dean was on his way to winning the polls when he blew it in one horrific moment. He was fired up during a rally, promising to "TAKE BACK THE WHITE HOUSE" when he just let out a legitimate scream. Historically, he did not win.
Stephen Collins
Former "7th Heaven" star Stephen Collins was blacklisted from Hollywood after admitting that he had pedophilic tendencies. He'd admitted to inappropriate contact with a 10-year-old girl as well as three other minors. His wife swiftly filed for divorce and it's unlikely he'll ever work around children ever again.