Chip Knappenberger, a scientist with libertarian think tank the Cato Institute, describes how the former New Mexico and former Massachusetts chief executives would approach environment and energy issues if they governed America.
Many people hadn't heard of Gary Johnson before last night, but he's already presenting himself as a fiscally conservative libertarian with a proven track record of economic successes. How do his claims match up with reality?
Highlights from the third Republican debate: Texas Governor Rick Perry stumbles, audience boos Don't Ask, Don't Tell question from gay soldier, new candidate Gary Johnson joins the roster.