ESpen36's analysis leaves out the minor detail that TSA is plugging GE as a way around being groped, so people who don't travel internationally are also applying now.
Excellent point. I wonder how TSA reconciles this point.
Due process for something like this can be satisfied by something as simple as an administrative appeal. I suppose a final agency order could be reviewed under the APA.
Yes, I belive the OP can appeal the denial to the CBP Ombudsman for reconsideration. It might take a while, and in the meantime, it would be good for the OP to enter grad school full time or obtain full-time employment.