You could arm a small percentage, just so you'd have one guy on shift with a piece. There are enough ex-mil, LEO, etc in their ranks that you could do that safely.

But do we even need the expense? What laws would TSA have jurisdiction over? We already have local cops at essentially every airport, and TSA would have to call those folks anyway for many disruptive pax who don't manage to violate a federal law.

Most pax problems occur at the gate or on the airplane, after they liquored up, bumped from their flight, etc.