They only have to carry enough for those they choose to target for whatever nefarious reason. And believe me, I gave them reason enough when I wrote a "nasty-nice" letter to the editor nailing them for their misconduct in a traffic accident involving my son. I was on guard for forever, expecting them to target me or mine. I finally realized that they were more likely to go after those who are too ignorant or poor to fight back -- it also might have helped that I had a video of the accident scene that showed the evidence that the cop was wrong (a county cop happened to drive by while I was filming the scene, so they knew).
BTW, my son's former fiance had a cousin on the force and she was invited to the cops annual (and very secret) parties where the cops endulged in a wide varity of the drugs they had confiscated so these cops always have access to illicit drugs.
One last note, other than receiving an occasional speeding ticket, neither I, nor anyone in my family have ever been involved in criminal activity.
Sorry for the length, but I have not yet learned how to make a long story short.