The two biggest mistakes in the history of American politics:
#2: Teddy Roosevelt, before his inauguration ceremony in 1905, declared that he would not serve another term.
#1: The resignation of Sarah Palin as Governor of Alaska, after 2.5 years of her 4-year term, was announced on July 3, 2009 and became effective on July 26.
And where do you rank Ronald Reagan taking on George HW Bush as his Veep in 1980?