The term derives from the Sherman pledge, a remark made by American Civil War General William Tecumseh Sherman when he was being considered as a possible Republican candidate for the presidential election of 1884. He declined, saying, "I will not accept if nominated and will not serve if elected." Thirteen years prior, he had similarly asserted, "I hereby state, and mean all that I say, that I never have been and never will be a candidate for President; that if nominated by either party, I should peremptorily decline; and even if unanimously elected I should decline to serve." These statements are often abbreviated as "If drafted, I will not run; if nominated, I will not accept; if elected, I will not serve.
Draft folks who might(?) not only want it but who might actually win it, Here's one example aside from the usual suspects and the anointed.
In March 2011, Sherrod Brown came under scrutiny for a senate floor speech in which he cited the names of Adolf Hitler and Joseph Stalin while he criticized Republican efforts in Ohio and Wisconsin to mitigate the power of public employee unions to negotiate with taxpayers. In his speech he said "some of the worst governments that we've ever had, do you know one of the first things they did? They went after unions. Hitler didn't want unions, Stalin didn't want unions, Mubarak didn't want independent unions". Brown, however, added that he was not comparing the two situations. He later apologized for his speech