Aside from once-and-future President Donald Trump's unexpectedly decisive win, one of the most surprising results in Tuesday's election was Republican Dave McCormick's apparent victory over three-term U.

One of Pennsylvania's two U.S. Senate seats is before voters Tuesday, with Sen. Bob Casey vying for a fourth term against challenger and businessman Dave McCormick. It is expected to be a close race and could ultimately play a role in the balance of power in the Senate.