Former Alaska Gov. Sarah Palin, center, visits a Civil War-era cemetery, Tuesday, May 31, 2011, at Gettysburg National Military Park.
Timothy Jacobsen/AP
hide caption
Army Chief of Staff Gen. Martin Dempsey pauses before speaking to family members of fallen service members at a Tragedy Assistance Program for Survivors seminar.
Evan Vucci/AP
hide caption
President Obama, with Facebook CEO Mark Zuckerberg, speaks during a town hall meeting April 20 at Facebook headquarters in Palo Alto, Calif.
Mandel Ngan/AFP/Getty Images
hide caption
Former Alaska Gov. Sarah Palin greets some of the thousands of motorcycle enthusiasts and military veterans participating in the Rolling Thunder rally on Sunday.
Chip Somodevilla/Getty Images
hide caption
Corn is big business in Iowa, which has usually made anything but support for ethanol subsidies off-limits for presidential hopefuls.
Steve Pope/AP
hide caption
Sen. Rand Paul (R-KY) speaks during a Tea Party Town Hall meeting in February at the National Press Club in Washington. The freshman lawmaker is being hailed by civil libertarians for putting privacy concerns over the Patriot Act back in the spotlight.
Alex Wong/Getty Images
hide caption