Texas Rep. Ron Paul (right) talks with the his presidential campaign manager, Jesse Benton, backstage at the Republican Party's Iowa straw poll last August. Charles Dharapak/AP hide caption

itoggle caption Charles Dharapak/AP

Fans of GOP presidential candidate Ron Paul show their support outside the Mesa Arts Center before Wednesday night's Republican debate in Mesa, Ariz. Ethan Miller/Getty Images hide caption

itoggle caption Ethan Miller/Getty Images

Rep. Ron Paul, R-Texas, during Thursday night's Republican presidential debate in Jacksonville, Fla. Paul J. Richards/AFP/Getty Images hide caption

itoggle caption Paul J. Richards/AFP/Getty Images

U.S. Rep. Ron Paul, shown at a campaign stop in South Carolina, spoke with NPR's All Things Considered today about the upcoming primaries, the possibility of a third-party run, taxes and other issues. John W. Adkisson/Getty Images hide caption

itoggle caption John W. Adkisson/Getty Images

Ron Paul greets supporters in Meredith, N.H., on Sunday, two days before he placed second in the state's Republican primary. Stephan Savoia/Associated Press hide caption

itoggle caption Stephan Savoia/Associated Press

Mitt Romney speaks to supporters at Southern New Hampshire University in Manchester, N.H., after winning the state's primary on Tuesday. Win McNamee/Getty Images hide caption

itoggle caption Win McNamee/Getty Images

Ron Mirsky, 54, a customer at Me & Ollie's Cafe in Exeter, N.H. — the town where Ron Paul announced his run for president — says Paul has interesting ideas. John Winslow Poole/NPR hide caption

itoggle caption John Winslow Poole/NPR

Ron Paul spoke to a packed house at the Knapp Learning Center during his "Salute to the Military" event in Des Moines, Iowa, on Wednesday. Becky Lettenberger/NPR hide caption

itoggle caption Becky Lettenberger/NPR