The above map (click to enlarge) shows gay marriage rights (or lack thereof) in all fifty states. If Washington passes the domestic partnership legislation introduced yesterday, it will join Vermont and New Hampshire as the only states with (roughly) marriage-equivalent civil unions and only a statute preventing gay marriage.
Oregon and California grant such unions but have constitutional bans on gay marriage, while Massachusetts and Connecticut go all the way and have gay marriage.
That red mass in the middle and lower-right represents states whose constitutions ban gay marriage and civil unions. May God smite them.