If there was ever a good indication that the Washington Top 2 primary is a good indicator of future performance, take a look at this SurveyUSA poll of WA-03. In last week's primary, the Democratic candidates (Denny Heck + Cheryl Crist) got 42% and the Republican candidates got 54%. Those votes seem to have flowed unimpeded to the nominees, Heck and Jaime Herrera, with Herrera leading Heck 54-41.
Looking at the crosstabs, the sample is very top-heavy with oldsters (62% are 50+, and 68% report incomes of $50K or more). Not that it matters: the support for Herrera is pretty consistent across all age groups (54% or 55% in all four groups), though. With Herrera already over 50%, Heck is either going to have to change some minds quickly, or else hope (like a lot of other Dems) that the universe of likely voters gets bigger (and younger) than it is now.