republican running for the gop nomination. so ron paul throwing his hat into the ring. swreel more on that in our political segment just up ahead. well, cnn in depth. troubled waters. along the lower mississippi river there is a nervous wait-and-see. it is likely that the morganza spillway will be opened to keep major floodwaters away from new orleans. but what that does, it puts other cities and towns basically in harm's way. and they're getting prepared. our cnn's ed lavandera. >> start pumping the water out when it starts coming in. >> reporter: gerald will fight off the watt we are a little bayou ingenuity, his homemade levee wall. do you think this wall will be enough? >> i'm hoping so. if it gets any higher, ain't going to be much in the neighborhood for sure. >> reporter: disaster is flowing downstream and residents in towns like stevenville and morgan city are at the end of the line. >> the closer it gets, starting