TNR senior editor Jonathan Chait discusses his last "TRB From Washington" column with editor Franklin Foer: What made Republicans decide to hop on the crazy train--ignorance, panic, or ideology?

Check out the latest on TNRtv:

Obama's 'Drug Czar' on the Mexican Drug War

Johnson: Geithner May Be More Arsonist Than Firefighter

Halevi: Obama's Arrogance May Ignite The Middle East