The marriage equality bill in the Washington senate is just one vote shy of the 25 needed for passage following an announcement from Democratic senator Jim Kastama, while businesses including Microsoft and Nike have also announced their support for the measure.

Kastama, a conservative Democrat from Puyallup south of Seattle, announced his decision at a news conference Thursday afternoon. He said his constituents expected him to be "fiercely independent," although he believed some voters would never approve of his decision.