To my surprise, the fight to keep telecom companies from not being held liable for spying on Americans has continued, as for once, the Democrats aren't just rolling over for Bush. They're actually fighting him on this. So as the economy goes south and is increasingly getting the attention and concern of more and more Americans, "national security" is fading away in importance, and Bush can no longer scare congressmen into blindly supporting him.
So, in his desperation, he's now saying that we have to give immunity to the telecoms so as not to let the big, bad "trial lawyers" make money off them in lawsuits. The constitution shouldn't factor into this at all, just can't let the "trial lawyers" get their way.