I ended up in a vacation resort in the West Indies with little to do, and stumbled across a book by Jules Witcover on the 1976 election. It sparkled my interest in US elections, in fact. But it was a really thick book...
Okay. I like the 1912 election because it is the only election I can find where 4 candidates polled over 10% in a state. Wilson, Taft, TR, and Debs all did this in Idaho in 1912.
Actually, all 4 broke 15% in either Oklahoma or Nevada. It was a very chaotic year, and Debs and Wilson were the only ones on the ballot in all the states. TR and Taft managed to block eachother in one state.
Edit: This is what I get for not reading the whole thread before posting...