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,

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.

Republican Dave McCormick's lead over Democrat Bob Casey is within the 0.5% margin that would trigger another tally.

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

Pennsylvania Sen. Bob Casey is vying for a fourth term against challenger and businessman Dave McCormick in an extremely close race that could ultimately play a role in the balance of power in the United States Senate.

"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.

As of early Wednesday morning, 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. While Casey held a lead for much of the campaign,