You prevent kids from joining gangs by offering after-school programs, sports, mentoring, and positive engagement with adults. You intervene with gang members by offering alternatives and employment to help redirect their lives. You deal with areas of high gang crime activity with real community policing. We know what works.
The draconian spirit that seeks to enhance penalties and to lower the age at which juveniles will be tries as adults, is part of the 'whole cloth' of three strikes. Our failure to address the depair of our inner-city youth is only delayed by our over-confidence in a stance that is 'tougher than thou.'