SPOKANE, Wash. -

The race for one open U.S. House seat and dozens of legislative contests highlight a less-than-scintillating primary election ballot in Washington state on Tuesday.

Only about 40 percent of Washington's registered voters are expected to cast ballots in the primary.

David Ammons, spokesman for the secretary of state's office, says that prediction may even be high. He says California and Oregon reported record low turnouts in their primaries.

Ammons says the 40 percent prediction is based on the past two midterm primaries in Washington. But those elections featured contests for a U.S. Senate seat.

There are no candidates for statewide office this year.

The election is entirely vote-by-mail, which means between 50 percent and 60 percent of the vote should be tallied and released on Tuesday evening.