The U.S. Senate election in Pennsylvania between Democratic incumbent Sen. Bob Casey and Republican David McCormick is headed for a statewide recount, as counties continued Wednesday to sort through outstanding ballots and the campaigns jousted over which ones should count.

The incredibly tight Pennsylvania race between Democratic Sen. Bob Casey and Republican challenger Dave McCormick will head to a recount, Pennsylvania Secretary of the Commonwealth Al Schmidt announced Wednesday.

Our averages include polls collected by The New York Times and by FiveThirtyEight. The estimates adjust for a variety of factors, including the recency and sample size of a poll, whether a poll represents likely voters, and whether other polls have shifted since a poll was conducted.