The New York Times offers this report. A snippet:

Many politicians are also keeping a close eye on population movement within the state.
Within 48 hours after Hurricane Katrina made landfall, Baton Rouge became Louisiana’s largest city, doubling to about 800,000 residents. Local officials are now trying to get a population survey up and running to seek federal aid.
Mr. Koepp said this population shift could actually be the early stages of the deterioration of New Orleans’ long-term hold over the State Legislature. “If this holds true, there will be a significant political change,” he said.
There are now 21 seats in the House and Senate that encompass or touch on Orleans Parish, of 144 total seats statewide.
But if the population fails to return to the parish in coming years, New Orleans may be confined to just a few seats in each chamber through redistricting, Mr. Koepp added. That could change the state’s racial and partisan balance.
If evacuees from the Ninth Ward in New Orleans – a reliable bloc of 30,000 black voters that is traditionally easy to mobilize – choose suburban or rural areas over their urban roots in coming years, it could be a political blow to Democrats, said Roy Fletcher, a political consultant from Shreveport who helped elect former Gov. Mike Foster, a Republican.
“It would give a whole lot of a stronger foothold to Republicans in the Legislature and statewide,” Mr. Fletcher said. “Louisiana has always been a swing state, a purple state that’s both blue and red. You take the Ninth Ward out of that equation and you get a real shot of Republicans winning statewide office.”

Thanks to Election Updates for the pointer.