PHILADELPHIA (AP) — Former Pennsylvania congressman Joe Sestak began a 422-mile walk across the state Wednesday to kick off his campaign to capture the U.S. Senate seat occupied by Republican Pat Toomey. The casually dressed Democrat then changed out of a pair of high-top Reeboks and put on military-issued boots to walk a few blocks to the city's Vietnam Veterans Memorial. Toomey's campaign did not return a request for comment, but the National Republican Senatorial Committee issued a statement saying that Pennsylvania voters already rejected Sestak's "partisan agenda" five years ago. Sestak's 31-year Navy career included commanding an aircraft carrier battle group in Afghanistan and Iraq following the 9/11 terrorist attacks.