Gustav had nothing to do with the turnout of this election.
I’m pretty sure I remember reading something to that effect on NRO refering to his election in the aftermath of Rep. Jefferson situation.
What did? Why was the election held late? Simple New Orleans incompetence?
According to the LA Times,
Although blacks make up more than 60% of registered voters in the 2nd Congressional District -- which covers much of New Orleans and part of neighboring Jefferson Parish -- fewer than 14% showed up Saturday, according to a consulting firm that worked for Cao's campaign. By comparison, 28% of white voters went to the polls, largely in support of the Republican. Vietnamese Americans account for less than 3% of district voters.
Even so, Cao won with 49.6% to Cold Cash Jefferson's 46.8%. The Greenies took up most of the rest.
If Cao had the right stuff, he would have known there's no chance of his reelection. He would have raised his middle finger to his constituents and voted correctly. Then, after his term, if he still wanted to be in politics, he'd move somewhere else.