The tribes that have adopted gambling are probably the least likely to embrace any terrorist organization. Instead they are embracing capitalism and the great pursuit of the all mighty dollar. What could be more American? Instead of looking at the tribes that are on the move maybe you should look at the tribes that are going nowhere, for evidence of harboring your malcontents, subversives and terrorists.
Like I said, since they are separate nations within our borders, they bear scrutiny. All of them.