What's the thought process behind picking a supreme court justice without any judicial experience? Is there an argument for that?
Sure, there are some pretty good arguments. It broadens the perspective of the court to have some people who come from outside of the judicial fraternity. Usually, that involves getting someone who has a broader experience outside of the court system, although in Kagen's case she has been equally cloistered in legal academia, punctuated with service in the executive branch of the federal government. I'm not sure the addition of Kagan, therefore, will serve the purpose.
Frankly, it troubles me more that Kagen has served in the executive branch than that she hasn't served in the judicial branch. We're seeing a growing trend whereby presidents choose justices who, having served past presidents, are expected to be more sympathetic to executive claims in the future. Indeed, Kagan has received exactly this criticism. She's no Harriet Myers, to be sure, but time will tell whether she can stand up to presidential claims to power.