Speaking of upside-down preemption, the United States faced a lot of skepticism from the Supreme Court yesterday over its aggressive attempt to strike down Arizona's anti-illegal-immigration law, SB 1070. As Michael Greve argues, "far from conflicting with federal law, S.B. 1070 complements it." More: Levey; Reason; WaPo; SCOTUSblog.

Earlier on POL: Shapiro podcast; Romney campaign; upside-down preemption; rule of law and the Obama administration.