The Pennsylvania special congressional election is too close to call.
Democrat Conor Lamb and Republican Rick Saccone are battling for a seat in the U.S. House of Representatives to represent the state's 18th district. The winner will replace Rep. Tim Murphy, who resigned last year amid reports he asked a woman with whom he was having an affair to have an abortion.
If Lamb wins, it will be a huge score for his party. President Donald Trump won the 18th district by 20 points in 2016, and the voters there haven't sent a Democrat to the House since 2000. A Lamb win could also be a sign of what's to come in other congressional races later this year.