The FiveThirtyEight.com election simulator identifies "Tipping-Point States": states that would be most likely to alter the outcome of a close election. More specifically, they are the closest states--alone or in combination--that would give the losing candidate at least 270 electoral votes if transferred from the winner's column. Consider: John McCain won't win Minnesota without having won Wisconsin, and he won't win Wisconsin without having won Michigan--and if he's won Michigan and Wisconsin, he's the next president. So Minnesota isn't as important as it might appear. The figures on the map show the percentage of the times in 10,000 simulated elections that a certain state was the Tipping-Point State. The conclusion: Michigan and Ohio are most likely to tip the election. Which makes sense: They are very middle-of-the-road states, not just politically but also demographically. If Barack Obama is to pull of winning Indiana or Missouri, say, he will probably have had to win Ohio and Michigan first--or likewise for John McCain in Pennsylvania.