Democratic U.S. Sen. Bob Casey and Republican challenger David McCormick met for their first debate in the Pennsylvania U.S. Senate race, with each candidate repeatedly accusing the other of lying.

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

From border security to nuclear energy, the candidates turned almost every question thrown at them into an opportunity to drive home their narratives about each other.