The massive population shift caused by hurricanes Katrina and Rita holds seismic political implications for Louisiana, which faces a near-certain reduction of its congressional delegation and a likely loss in black-voter clout that could severely affect the state's elected Democrats.

Less than two months after Katrina devastated the Gulf Coast, leaving much of New Orleans and surrounding areas unlivable, Louisiana officials are beginning to grapple with the bewildering new political landscape. The storms and resultant flooding caused more than 1 million residents to flee their homes, many for far-flung destinations from which they may never return.

In a public service announcement released yesterday, Coast Guard Vice Adm. Thad W. Allen, who is in charge of the federal government's recovery effort, said: "In many areas, like the Lower Ninth Ward of New Orleans . . . the areas will be uninhabitable for many years."

The unprecedented population shift is likely to have its first political impact in New Orleans, where Mayor C. Ray Nagin, who captured 44 percent of the black vote in 2002, and other municipal officials are facing a February election.

The election will be one of the most important in the city's history, with the winners set to play a pivotal role in deciding how the city will be rebuilt. But with only a smattering of the city's 484,000 residents back home, it will also be an election in which voters will be difficult to find and residency hard to prove, leaving candidates unsure of how to campaign.

"I'm in Jackson, Mississippi, at a hotel now -- does that make me a voter here?" asked Vincent Sylvain, a New Orleans voting rights activist. "We are citizens of Orleans Parish in the state of Louisiana and must maintain our right to vote here. That's the only way we can hold elected officials accountable."

Officials are undecided on how to conduct the election. Some have suggested opening polling places in Houston, Memphis, Atlanta, Baton Rouge, La., and other cities that house large numbers of evacuees. Others have suggested electronic voting. Officials are hoping to secure funding from the Federal Emergency Management Agency to pay for radio and television ads to publicize the election to evacuees.

Louisiana Secretary of State Al Ater has formed a task force of party leaders, elected officials and civil rights advocates in an attempt to sort out the layers of issues presented by the evacuation.

In New Orleans alone, nearly half of the voting precincts were destroyed by Katrina. Many of the neighborhoods most affected include overwhelmingly Democratic black communities in the Seventh, Eighth and Ninth wards. And while many African American voters remain in Louisiana, a number significant enough to affect a close election have left.

In political circles last month, "there was talk that the Democrats' margin of victory [in Louisiana] was living in the Astrodome in Houston," said Ronald D. Utt, a senior researcher at the Heritage Foundation.

That reality has left some Democrats concerned that the party could lose its tenuous grip on power. Both Gov. Kathleen Babineaux Blanco's 2003 election win and Sen. Mary Landrieu's 2002 reelection victory came with margins of fewer than 60,000 votes, which included overwhelming support from African Americans.

"All of that's gone. So you are going to have a restructuring," said state Sen. Derrick Shepherd (D-New Orleans), a member of the elections task force.

Also, Louisiana is likely to lose one of its seven congressional seats -- a prospect that had loomed before the storms and has now been solidified because of the state's population loss.

With Louisiana subject to provisions of the Voting Rights Act requiring the U.S. Justice Department to approve any substantive changes in election districts and processes, national civil rights organizations are keeping close watch on how political power in the state is being reshaped.

"We are concerned that there are both a land grab and a power grab going on," said Theodore M. Shaw, president of the NAACP Legal Defense and Educational Fund. "If there is not a significant return of black residents to New Orleans in the near future, at what time will there be an attempt to redistrict?"

Although Nagin and other officials have been campaigning to persuade residents to return to New Orleans, it is unclear how many plan to come back. In a survey of 680 randomly selected New Orleans evacuees at eight Houston shelters conducted Sept. 10 to 12 by The Washington Post, the Henry J. Kaiser Family Foundation and the Harvard School of Public Health, about 44 percent said they do not intend to return home.

Already, a Republican congressional candidate has noted that if depopulated parishes are subtracted from his district, Rep. Charlie Melancon (D), who won election with 50.2 percent of the vote in 2004, would have received 43 percent of the vote.

In comments to the Houston Chronicle, Housing and Urban Development Secretary Alphonso Jackson triggered a controversy by acknowledging that New Orleans will lose population because of Katrina, and suggesting that parts of the low-lying Ninth Ward may never be rebuilt.

"Whether we like it or not, New Orleans is not going to be 500,000 people for a long time," he said. "New Orleans is not going to be as black as it was for a long time, if ever again."

Adm. Allen said Wednesday that Louisiana storm victims who need the government's help with housing will be offered choices on where to settle, but only after it is determined that they cannot return to the state. "The premium is going to be placed on putting [people] in Louisiana, because that's the governor's wish, and we support that," he said.

Kim Hunter Reed, Blanco's director of policy and planning, acknowledged the state's interest in retaining its residents, but said the test will be whether southern Louisiana can be rebuilt into a place worth returning to, with jobs, strong schools, health care and housing.

"Obviously, we have a great interest in bringing our citizens who are out of state back to Louisiana as close to their homes as possible and back home," Reed said. "We know our citizens will have a yearning to return home, and we want our state to be ready to receive them."