Drudge is all excited about various previous executive orders. Anyway, I'll let others do the heavy lifting on the precise legalities but right or wrong the argument was always that those executive orders fell clearly within the framework of the FISA statute. In addition those executive orders were, you know, not secret executive orders. The Bushies have argued that what they did was explicitly and deliberately outside statutory authority, or at least they started to argue that once their criminality was no longer secret. It's one thing to claim "law x gives me the right to do y," make that public, and give a court and congress the opportunity to slap you down. It's another thing entirely to say "fuck congress and fuck the courts."