WASHINGTON (AP) -- Population shifts caused by the exodus of hurricane victims from the Gulf Coast could have ripple effects for years to come in Louisiana political races and perhaps beyond. How big depends on how many people stay away, which ones stay away and where they end up putting down roots. The early thinking is that the evacuees least likely to return to their homes in Louisiana may be the poorest -- and thus, Democrats for the most part. That would hurt the party in a state where Republicans already were making inroads. If the lion's share of those...