If a person shows up without his passport or other border crossing ID (passport card, nexus, or enhanced license) it is pretty easy to look up the data for those which include a picture. There might be civil penalties involved, but they still can't deny you entry.
It might take a while, but they cannot deny a USC entry to the U.S.
65 posted on 03/31/2012 8:38:56 AM PDT by USNBandit
(sarcasm engaged at all times)