The 2012 presidential campaign takes place at a time of deep political division in the United States. Democrats and Republicans differ sharply over Barack Obama's performance in office as well as a wide range of issues ranging from government spending and health care to immigration and gay marriage. These divisions are shaping the strategies of the candidates and the outlook for November. Overwhelming majorities of Democrats and Republicans, including overwhelming majorities of independents who lean toward a party, can be expected to support their own party's nominee. As a result, the outcome will depend on which party does a better job of mobilizing its supporters and appealing to a small group of swing voters in 10 or 12 battleground states.