Long thread with good info so this may have been said and I missed it:

When you change the administrative function to one in which firearms are introduced creating a quasi-LEO organization, the constitutionally permissible universe of allowable behaviors is greatly reduced. The only reason the TSA exists as is does is the loosened protections of the administrative search doctrine and its court allowed carve outs to 4th Amendment protections that law enforcement officers generally do not have. There are exceptions, random sobriety checks for instance, but they are few and and tightly regulated. The TSA as we know it would cease to exist with LEO type regulatory oversight.

That may or may not be a good thing.