Preview: Proving Grounds: New Hampshire

A state known for dirty political tricks, the South Carolina presidential primary has picked nearly every nominee. Take a look back at who had sharp enough elbows to win this important election and who fell victim to the questionable campaign tactics.

New Hampshire is a small state with a big impact on American politics. Hear from former presidential candidates about how their first-in-the-nation primary has produced some of the most dramatic moments in campaign history, and how the state has influenced the U.S. political landscape for decades.

Presidential hopefuls devote more time and money to Iowa than any other state. Past caucuses have catapulted long-shots and crushed front-runners. Why is this quirky election first in the country and how important are Iowa's citizens in deciding who will lead the most powerful nation in the world?