For months, Pennsylvania was considered a cakewalk for Democrats, with Sen. Bob Casey easily cruising to reelection and its 20 electoral votes in the bag for President Barack Obama. But enter Republican Tom Smith and his personal fortune, and suddenly the Keystone State has the potential of upending the national political landscape. Buoyed by a tightening presidential race here, Smith — a no-name GOP Senate candidate and self-funding multi-millionaire — has suddenly made Republicans bullish about picking off the Keystone State to make Mitch McConnell majority leader and Mitt Romney more competitive here. “He wasn’t on any endangered list,” Rep....