Democratic Sen. Bob Casey went head-to-head with Republican Dave McCormick in a bitter first debate that reflected the close nature and high stakes of the race

Democratic U.S. Sen. Bob Casey of Pennsylvania and Republican challenger David McCormick met Thursday for their first debate in the pivotal race for a swing-state seat, with each candidate repeatedly accusing the other of lying and turning questions about energy,

The candidates battled throughout the debate, often claiming the other was lying on the campaign trail and on the debate stage.