So various state legislatures are trying to nullify Federal laws they don't like? Good luck with that. We've been trying to do that with Federal marijuana legislation here in California for the past 30 years, but the DEA still does regular drug raids.
The typical argument is that the 10th Amendment gives all rights not explicitly dedicated to the federal government to the states. Yawn. William Tecumseh Sherman pretty much nullified the 10th Amendment when he burned and raped his way across South Carolina to punish them for putting state supremacy ahead of federal government supremacy. I'm seeing nothing saying any of this nullification legislation is going to be any more enforcible than South Carolina's declaration of secession from the Union was. Well, South Carolina managed to enforce their secession from the Union for four years, but we all know what happened there in the end... as Governor Earl Long of Louisiana is reputed to have said when the Lege urged him to defy a Federal desegregation order in 1958, "Are you fucking nuts?! We're talking about the U.S. government, they got the goddamned atomic bomb!"
In the latest silliness, the State of Texas is trying to "nullify" the TSA checkpoints in airports. Yeah, good luck with that. Governor Faubus of Arkansas tried something like that too back in 1957. Didn't quite work out for him:
The 101st Airborne kinda outguns and out-mans the Texas Rangers. Just sayin'!-- Badtux the Reality-based Penguin

