This is the results map of the US elections :

According to the map, Obama, who supports the democratic side, won the election with 53% of the vote ( I.e. 66,316,572 voters) against 46% ( I.e. 58,013,719 voters) for McCain, a Republican candidate.
We can notice that in the seven battleground states : 4 voted for Obama, 2 for McCain and one state, Missouri, was undecided.
Many states change their opinion about their party especially Nevada, Colorado, New Mexico, Iowa, Indiana, Ohio, North Carolina, Virginia and Florida which voted for the Republican party , led by George W. Bush in 2004 and voted for Obama this year.
Obama were elected because many young adults could vote this year and they realise that they need that things change.
People need change because Bush’s policy disappointed Americans.
However, states, especially those in the south, voted for McCain because of racism
(=> It was there that segregation was strongest in America) and also because McCain based his campaign on the families’ values.