Recommended by Eugene Volokh, the National Constitution Center’s “Interactive Constitution“. Its description:

On this site, constitutional experts interact with each other to explore the Constitution’s history and what it means today. For each provision of the Constitution, scholars of different perspectives discuss what they agree upon, and what they disagree about. These experts were selected with the guidance of leaders of two prominent constitutional law organizations — The American Constitution Society and The Federalist Society.

The writers include many familiar names and every contribution I’ve read so far, on both sides of questions, has been of high quality.

Filed under: constitutional law, First Amendment, Fourth Amendment, guns