Harvard's Kennedy School provides a Google custom search that will search Web publications from a large number of 'think tanks'. Enter your search term(s) in the box as in any Google search. The organization names are links to the respective Web sites.
Very useful site for keeping up with key controversial public issues. Scroll down to the bottom of the home page for links to the issues. There are many documents, reports, and other materials deeply linked within the site.
Full-text research reports on many topics of public policy debate. Hover over the Research tab to display topics, research programs, and featured research articles. Select a topic to reach subtopics and more.