Usually Sunday morning talk show panel discussions are little more than conventional wisdom echo chambers. Talking heads take turns trying to prove just how reasonable they are in the most cordial and polite way possible. No need to break up the chummy atmosphere by actually arguing over anything of substance.

Sometimes someone pushes through the nonsense. This weekend, Glenn Greenwald took that role on ABC’s This Week where he completely destroyed former Obama White House counsel Greg Craig in an argument over Supreme Court nominee Elena Kagan’s lack of identifiable views. Check it out: