Thomas Eagleton was briefly the running mate of George McGovern in 1972. Facing a massive uphill battle to defeat Richard Nixon, many of the largest names in the Democratic Party, including cluding Ted Kennedy, Walter Mondale, Hubert Humphrey, and Birch Bayh declined to be on the ticket. As McGovern searched for a running mate, he eventually settled on Tom Eagleton, which ended up being the first of a series of disastrous mistakes made by the McGovern campaign.
Before Eagleton was selected as McGovern's running mate, he had anonymously given a quote to Robert Novak stating "The people dont know McGovern is for amnesty, abortion and legalization of pot." Nevertheless, Eagleton wasn't revealed as the source of the quote until after his death, though he knew at the time that it would be costly for his political career should the quote be revealed.
Shortly after Eagleton was selected, it was revealed that he was on Thorazine, a powerful anti-psychotic medicine, and the prescription was written under his wife's name. Eventually, McGovern discovered that Eagleton's records contained references to "manic depression" and "suicidal tendencies." After initially stating his "1000 percent support" of Eagleton, he later asked Eagleton to resign from the ticket.
Despite polling that showed that most Americans would not be swayed by Eagleton's condition, the press made frequent references to 'shock therapy', and McGovern felt it would distract from the platform. However, the damage had already been done. Republicans used the scandal to question McGovern's decision making, and McGovern only carried 17 electoral votes, and suffered the largest popular vote defeat in American history. Eagleton, on the other hand, was elected to two additional terms in the United States senate before retiring.