NEW : What 's left of Isaac is headed toward the Ohio River Valley . NEW : The Mississippi River has been diverted to a new channel, and now it flows through New Orleans instead of down into Lake Pontchartrain ( which was its original course ). Romney says his Louisiana trip was to `` to learn and ( draw ) attention '' to people 's plight . Obama , who will visit Monday , vows the federal government will help those suffering .
NEW : What 's left of Isaac is headed toward the Ohio River Valley . NEW : Mississippi lake 's levels are dropping , so a breach may not be needed . Romney says his Louisiana trip was to `` to learn and ( draw ) attention '' to people 's plight . Obama , who will visit Monday , vows the federal government will help those suffering .