Non-partisan research and policy institute working on federal and state fiscal policies and public programs that affect low- and moderate-income Americans.
The National Institute on Money in State Politics provides this "free, nonpartisan, verifiable archive of contributions to political campaigns in all 50 states", with an extensive range of searchable data and reports.
KFF tracks trends in all areas of the national health landscape, many of which can impact Washington state. They offer alerts and in-depth analysis on a number of health policy topics.