If the polls just closed, how can AP already declare a winner?

Associated Press

WASHINGTON (AP) — Election night won’t be all nail-biters. Chances are some winners will be declared before a single vote has been tallied just as the polls close in those states. Race calls at the time polls close have been a routine part of election nights for decades, even though competitive races that can take hours or even weeks to decide tend to attract the most attention. The Associated Press will consider multiple factors and analyze available data before determining whether a winner can be declared when polls close in a given state. The AP will never declare the outcome in a competitive contest before enough votes are counted to make the winner clear.