The atomization of New Orleans has done more to destroy the political fabric of the post-Katrina city than even some of the most concerned observers had dared imagine.

In a community that last elected a white mayor when Richard Nixon was serving as president, three white candidates – Louisiana Lieutenant Governor Mitch Landrieu, wealthy civic leader Ron Forman and Republican lawyer Rob Couhig – collected 56 percent of the vote in the first mayoral vote after last fall’s hurricane swept much of the city’s minority population away to Houston, Atlanta and more distant locations.

With turnout among the African-American diaspora low, Mayor Ray Nagin, the most prominent African-American candidate, won just 38 percent. He’ll face Landrieu, who took 29 percent, in a May 20 runoff election.

This is the first time since 1982 that a New Orleans mayor has been forced into a runoff, and if the May voting breaks along racial lines, the incumbent could become another victim of Katrina.

Will such a split occur?

Certainly the federal government, which should have worked from the start to assure that a natural disaster did not shift the political dynamic in a major American city that has long been under Voting Rights Act oversight, has done little to avert it.

From the White House’s shifting of funds away from infrastructure programs that could have protected the city’s poorest neighborhoods, to President Bush’s initial neglect of the crisis, to the move-‘em-on-out response of federal agencies to the plight of displaced residents, to House Speaker Dennis Hastert’s speculation about whether it made sense to rebuild, to the disengagement of the Justice Department from the serious debates about voting rights that arise when citizens have been turned into refugees, Washington has been no friend to democracy in New Orleans.

Sincere pundits will long debate whether the pattern of neglect was intentional. But few deny that it is to the advantage of the Republican Party that currently dominates federal politics to break up the urban voting bloc that has made New Orleans one of the most Democratic cities in the south and kept Louisiana far more politically competitive – with a Democratic governor and a Democratic U.S. Senator – than most of its neighbors.

Those who would prefer see the political complexion of New Orleans shift may not get their wish, however.

A May 20 result that divides the city along racial lines is at least a bit less likely in a Nagin-Landrieu runoff than it would have been in a contest between the mayor and one of the other white contenders.

Nagin was beat an African-American foe in 2002 with strong backing from the white community. While the mayor’s reelection campaign was targeted minority voters – stirring some negative attention nationally when he suggested that New Orleans would emerge as a “chocolate city” — surveys suggest that he retains a base of support among white voters. Nagin retains the potential to build on that base as he competes in the runoff.

Landrieu is the son of legendary former Mayor Maurice Edwin “Moon” Landrieu, who was one of the few white politicians to fight the segregationists in the 1960s and who went on to serve as former President Jimmy Carter’s Secretary of Housing and Urban Development. The son has worked to maintain the multiracial coalition his father built.

Speaking to supporters Saturday, Landrieu struck the right note for a runoff campaign that will test the political maturity not just of New Orleans but America. “Today in this great American city, African-American and white, Hispanic and Vietnamese, almost in equal measure came forward to propel this campaign forward and loudly proclaimed that we in New Orleans will be one people, we will speak with one voice and we will have one future,” he said. “We have said loudly and clearly that we will push off the forces of division and that we will find higher, common ground than we tried to find on that fateful day, Aug. 29, 2005, when we literally found ourselves in the same boat. We were in the same boat then and we are in the same boat now.”

No matter who wins the runoff, everyone who believes that America can and must continue to promote a politics of empowerment and harmony should hope that Landrieu proves to be right about the potential to unite a city that nature and Washington have done so much to break apart.