The only upside I see is that it might take Cantwell down with it if the WA 'Pubbies decide to keep the issue alive. I don't see Gregoire re-elected when it comes to that. This one is just a little too blatant.
The decision to go to Eastern Washington indicates a belief that a judge in Wenatchee and the state appeals court in Eastern Washington will give the Republicans a judgment calling for a new election. In the end it will go to the State Supreme Court.
On a parallel track, new AG Rob McKenna will be investigating the shenanigans in King County from a criminal point of view. Smaller fish will turn and bring in bigger fish, etc. The goal is to nail Ron Sims. Already there is word that the FBI is nosing around the King County elections office because a presidential election was involved. This increases the probability of something turning up.
Although the local MSM is in the tank for Gregoire, the bloggers are doing their job, and eventually one of the papers or TV stations will break the story. This is getting too big to hide.
By the time the State Supreme Court gets the case, I believe the intent is to have a combination of arrests and sourced stories in the MSM that will prevent the court from simply handing this one to the Democrats. The idea is to inform the public and get it riled up enough that a revote becomes inevitable.