On the West Coast, election doesn’t end on election night

OLYMPIA, Wash. (AP) — If control of the U.S. House comes down to any of the competitive congressional races in Washington state and California, it may take days to learn the outcome.

Three states conduct all elections exclusively by mail, but Washington is the only one of those that allows ballots to be postmarked up to Election Day. The system usually leaves about half of the vote outstanding at the end of the night, making it impossible to quickly know a winner.

Californians have the option of voting by mail as long as ballots are postmarked by Election Day and received no later than three days later. In past elections, some close races in California took several days to be called.

Colorado and Oregon require ballots be received by election officials by Election Day.