- Lincoln only won in 1860 because the Democratic Party was fragmented. Actually, Lincoln won 180 electoral votes -- almost 60% of the Electoral College. Even if all three strains of the Democratic Party had somehow unified behind one candidate, Lincoln still would have won. There were just far more voters in the free states.
- Kennedy only won in 1960 thanks to Chicago's Mayor Daley rigging the Illinois election. Nope. Kennedy beat Nixon by 84 electoral votes, and Illinois only accounts for 27 of those. Even if you give Illinois to Nixon, Kennedy's still president.
Update: For more on the 1860 election and its relation to the secession movement, please see this excellent piece by Susan Schulten, who, unlike me, actually does know what the hell she's talking about. Interesting point here:
A vote for Southern Democrats did not always predict secession. While a majority in Delaware and Maryland voted Southern Democrat, those states remained loyal. Conversely, in Tennessee Bell actually defeated Breckinridge, even though that state seceded in early June. Kentucky and North Carolina were split between the two parties, and while the former remained in the Union, the latter did not. The winner-take-all model of the Electoral College obscures this complexity.