This is another wonderful "non-story" whipped up by the media....
First of all, the Secret Service is so tight lipped about where the Prez is, they won't even say in advance. As an airline Captain, if Air Force One is on freq, they won't even tell me his position.
So, a guy decides to fly his 152 on a VFR day. Do you suppose he checked the 95 pages of NOTAMS that may or may not have had any info on the Prez? There's no way to cover small parts of a city so the only reasonable thing to do is to ground the entire area! How the heck are they going to do that? BS!
Do what they did when they used to move nuke warheads through town: Put a couple of choppers in the air as added protection and get on with life.
PT