Don't let these last two polls mislead you. Polling in the Murray-Rossi race has been totally confused lately.

Why? Poll-reading genius Nate Silver offers some thoughts:

One reason could be that [Washington] is one of two states, along with Oregon, where voting takes place almost entirely by mail. This can wreak havoc with traditional likely voter models, which often ask questions like, “Have you voted in the election precinct before?” and “Do you know where people in neighborhood go to vote?” — questions that are nonsensical in the context of an election that takes place by post. Also — probably because of mail balloting — turnout in Washington and Oregon has generally been very high, so targets that might work well in other states could fail there. Finally, since many voters in Washington return their ballots well in advance of Election Day, a pollster surveying the race close to Election Day will encounter another type of voter — those who claim to have voted already — which traditional likely voter models are not well designed to handle...

A few other things about Washington State are worth considering. First, Washington, a technologically savvy state, has a somewhat higher than usual number of cellphone-only adults, which pollsters may not be capturing. It also has a fair number of Asian-American voters, who can sometimes be hard to reach because of language or cultural barriers. These things could make a difference at the margins.