A lot will depend on what the Republicans do with the control. They are taking it because Washington is a deeply divided state on the state level. The Democrats have held out through their urban strongholds, but their recent blunders have hurt them deeply. it is a case of them pissing their advantage away as opposed to the Republicans siezing the heart and minds of the voting public.
Think Ohio without the high level scandals.
The GOP may pick up some seats iN Washington due to the problems the Dems have had, but the situation in Ohio iis much worse for the GOP than the Washington situation is for the Dems