Congressional Research Service Reports provide a variety of in-depth policy analysis and background summaries on every subject of interest to Congress. CRS is the nonpartisan research arm for Congress.
Here are 3 sources for CRS Reports.
This is a list of sources that summarize or comment on government policy. The list is arranged by prominence and then alphabetically.
The following think tanks are not included in NIRA's World Directory of Think Tanks. This list will be expanded as I come across them.