That could get real interesting. Particularly since there is no law requiring a person to even have an ID much less carry it at all times.
But I do seem to recall hearing about a SCOTUS case that declared that it is not a civil rights violation for a cops to ask for ID during during an investigative stop.
http://www.law.cornell.edu/supct/html/03-5554.ZS.html HIIBEL v. SIXTH JUDICIAL DISTRICT COURT OF
NEVADA, HUMBOLDT COUNTY, et al.
But this might not hold up in the Arkansas issue here. I suppose it will boil down to how liberal the cops want to be in defining investigative stop.