The Heritage Foundation and associated groups (including ALEC), the right-wing public policy institutes, and the right-wing legal foundations all work closely together. They have overlapping boards of directors, belong to the same umbrella organizations, and swap staff back and forth.
The umbrella organization for these right-wing think-tanks is the State Policy Network, which was founded by the Heritage Foundation. There's an excellent study from a few years ago, Target San Diego, which goes into many of these connections. The report itself is a fairly large pdf, but the non-pdf link to the download page is
http://www.onlinecpi.org/section.php?id=174.Here's a quote from the introduction:
The report contains sections covering the national, state and metro levels. Among the key findings are:
• National level organizations such as the Americans for Tax Reform, FreedomWorks and the American Legislative Exchange Council are deepening their ties with state legislators and policy organizations; while the State Policy Network strengthens existing state think tanks by developing their organizational structures, development operations and grassroots mobilization efforts.
• State level organizations such as the Project for California’s Future, Pacific Research Institute, Claremont Institute and Reason Foundation are linking the national conservative infrastructure with the right’s urban think tanks, corporate interests and party political structures.
• By developing a substantial independent media and research capacity, urban think tanks such as the Performance Institute in San Diego have developed an ability to drive policy debates, shape political campaigns and influence government decision making.
After presenting the case for the seriousness of the right’s challenge, Target San Diego recommends a concerted national effort by progressives to mount an adequate and strategically appropriate response.