Former U.S. Sen. Rick Santorum greets voters this summer in Iowa. The Republican presidential hopeful has spent most of his professional life in politics. Chip Somodevilla/Getty Images hide caption

itoggle caption Chip Somodevilla/Getty Images

A woman casts her ballot during early voting in Toledo, Ohio. Members of the silent generation are more likely to vote for Republicans than for Democrats, according to a recent study by the Pew Research Center. J.D. Pooley/Getty Images hide caption

itoggle caption J.D. Pooley/Getty Images

Union posters can be found all over the Occupy Philadelphia protest site near City Hall. Protesters and local union leaders meet regularly to discuss tactics and how to involve labor.

Jeff Brady/NPR hide caption

itoggle caption Jeff Brady/NPR

Chapman Corp. is expanding to take advantage of extra business it expects to get in coming decades because of increasing production in the Marcellus Shale play.

Jeff Brady/NPR hide caption

itoggle caption Jeff Brady/NPR

A protester marches on Friday in New York City as part of larger demonstration focused on corporations, wealth and income distribution. Mario Tama/Getty Images hide caption

itoggle caption Mario Tama/Getty Images