The tricky 2012 math for President Barack Obama

A candidate needs 270 of 538 available electoral votes to win the presidential election. The 2010 Census shuffled electoral votes to some fast-growing states, leaving others with less clout. This map shows how the states voted in 2008 with their updated electoral vote numbers for 2012. The 12 swing states all went Democratic in 2008. | Read Politics Editor Adam Smith's analysis of Obama's chances.

* Maine and Nebraska can split their electoral votes between two candidates.