CBP Refuses to Tell Congress How It Is Tracking Americans Without a Warrant
Congress has the power of the purse.  Failure to appear: no paycheck.  Multiple failure to appear: automatic departmental budget cut, ultimately to zero.  The executive may choose to illegally shuffle money around but that doesn't work for long.<p>Ironically the legislation that created DHS (a big mistake made opportunistically at the time) also included a GOP wish that made it not subject to the same set of employee rules the rest of the civil service is.*  So DHS is the easiest to do this with.<p>* It is still partially unionized, though the GOP tried to eliminate this when forming the department as well.