It would be interesting to give them some competition. Imagine if the department was split into the TSA and the TSB. Give them equal funding and presence in the airport. Flyers pay a screening fee and pick A or B, and then are screened by that agency. I bet they would shape up overnight.
[1] http://www.latimes.com/opinion/topoftheticket/la-na-tt-tsa-a...
[2] http://www.npr.org/sections/thetwo-way/2016/06/11/481694459/...