They couldn't immediately put that into place even if they were a competent administration, which they're not.
I find these arguments ineffective and I'll tell you why. Prior to 9/11, I was flying back and forth from Houston to Denver every week for about 3 months. In my laptop backpack, I carried a bunch of hand tools. Some of these tools consisted of - screwdrivers, pliers, and box cutters. I was installing a new wireless data network in Denver and it required these tools. The box cutters were used to cut and strip the weatherproofing on coaxial connections on antennas and radio equipment. Of all these weeks of flying, I was questioned twice about these tools - both times at DIA. One time, the security people at the xray scanners almost confiscated my tools. Mind you, these are metallic objects that could kill someone very easily.
Back to my point - All it would have taken was a directive from the president for these security checkpoints to start confiscating these types of objects. Simple as that. No long term or outlandish planning would be required to do this. Just an xray machine, a metal detector, and a trash can. Items which every airport already had. I don't buy into the argument that 1,000's more airport personnel would be required to do what I had already been through. Prior to 9/11, I would have understood the need to confiscate my job tools. But no one ever told them to do so until it was too late. Or was that the plan in the first place?