Former Massachusetts Gov. Mitt Romney campaigns at Ring Power Lift Trucks in Jacksonville, Fla., on Monday. Polls show him widening his lead in Florida after adopting a more aggressive campaign style. Charles Dharapak/AP hide caption

itoggle caption Charles Dharapak/AP

President Obama waves after speaking at a UPS facility in Las Vegas on Thursday. Nevada is one stop on the president's latest road trip focusing on the economy. Julie Jacobson/AP hide caption

itoggle caption Julie Jacobson/AP

Newt Gingrich arrives for a GOP presidential candidate forum Saturday in South Carolina. Gingrich had to be reminded of the rules not to mention rivals by name, but was still able to continue criticism of Mitt Romney. Joe Raedle/Getty Images hide caption

itoggle caption Joe Raedle/Getty Images