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,

Incumbent U.S. Sen. Bob Casey is not ready to give up his seat just yet, even as the margin of votes show the three-term senator trailing behind newcomer GOP candidate David McCormick in his re-election bid.

Casey v. McCormick tracks as second-most expensive race in the nation in a year where every seat counts in the battle for majority control of the U.S. Senate.