Didn't need to. The terrorists declared war on us way back in 1993. It wasn't until Bush came along that anything was done in response to the acts of war committed against us.
That still does not enable our government to suspend part or all of the Constitution. We must declare war and/or a state of emergency to do that.
Or, perhaps, we are already under a state of emergency that is being abused to selectively edit the Constitution.
An un-free dishonest nation isn't worth defending.