PHILADELPHIA — Pennsylvania’s nationally watched U.S. Senate race between Democratic incumbent Bob Casey Jr. and Republican challenger Dave McCormick was still too close to call as of mid-morning on Wednesday,

Republican Dave McCormick holds a narrow lead over Democrat Sen. Bob Casey in the U.S. Senate race in Pennsylvania, with final votes still being counted.

Pennsylvania's Senate contest between Democratic incumbent Bob Casey and Republican challenger David McCormick is still too early to call.

In the race for Pennsylvania's U.S. Senate seat, challenger and Republican Dave McCormick is leading over Democrat incumbent Bob Casey, but right now the race is too close to call. KDKA-TV's Jennifer Borrasso spent election night at the Casey headquarters and has reaction from Scranton.

Casey, 64, is a stalwart of the state’s Democratic Party, having won six statewide elections going back to 1996. But the vote count early Wednesday morning were suggesting that could change.

One of Pennsylvania’s two U.S. Senate seats is before voters Tuesday. Incumbent Democrat Bob Casey is vying for a fourth term against republican challenger and businessman Dave McCormick. Let’s start with incumbent Senator Bob Casey.

"Casey was running in a very tough environment for incumbents. ... People are sick of Washington and politics as usual," a political analyst tells Pittsburgh's Action News 4.

Pennsylvania’s U.S. Senate race between three-term Democratic Sen. Bob Casey and Republican David McCormick will help determine control of the chamber