This Demonstration examines the power the electoral college gives states in which the outcome of the popular election is unclear. It measures the power of these undecided states using the Banzhaf power index, which basically considers the relative power of each voting block (here the states) to "swing" the election, that is, cast a vote that changes the outcome. You choose whether the allocation of electoral votes is based on the 2000 census or the projected results of the 2010 census. You choose the candidate for whom the power of the undecided states is being considered—the power indices are often but not always similar for the varying candidates. You choose whether you want the Demonstration to produce a pie chart or a grid showing the relative power of the undecided states. You also choose whether you wish to display information comparing that power with the relative population of the undecided states. The relative population then appears as the inner circle of the pie chart or as the rightmost column of the grid. Finally, you assign states to one of the four possible candidates or leave the state undecided.