(CNN) -- Ray Nagin came into the mayor's office in New Orleans as an avowed scourge of corruption and led the city through the worst disaster of its modern history.
He left a federal courthouse a convict Wednesday, after a jury found him guilty of taking hundreds of thousands of dollars in bribes and other favors from businessmen looking for a break from his administration. Of the 21 counts against him, he was convicted of 20.
"He got a lot of media attention as being a reformer, a non-politician, first run for office -- a businessman who was going to come in and get it right," said Pat Fanning, a veteran New Orleans lawyer and no fan of the former two-term mayor.
After Hurricane Katrina ravaged the city in 2005, the onetime cable television executive would reassure people queasy about sending taxpayer money to a state with an epic history of corruption by telling them, "Google me. You're not going to find any of that in my record," Fanning said, quoting Nagin. "Well, Google him now."
Nagin, who left office in 2010, had little to say as he left the courthouse Wednesday afternoon, telling reporters only, "I maintain my innocence." A small knot of supporters yelled, "Keep your head up" and "He's just a patsy," CNN affiliate WDSU reported.
His lead attorney, Robert Jenkins, told reporters his client would appeal the verdict.
"We did the best we could do," Jenkins said.
Prosecutors argued the 57-year-old Nagin was at the center of a kickback scheme in which he received checks, cash, wire transfers, personal services and free travel from businessmen seeking contracts and favorable treatment from the city. He faces up to 20 years in prison, but Fanning said a 14- to 17-year term was more likely.
A January 2013 indictment detailed more than $200,000 in bribes to the mayor, and his family members allegedly received a vacation in Hawaii; first-class airfare to Jamaica; private jet travel and a limousine for New York City; and cellular phone service. In exchange, businesses that coughed up for Nagin and his family won more than $5 million in city contracts, according to the January 2013 indictment.
During the two-week trial, prosecutors brought to the stand a string of businessmen who had already pleaded guilty to bribing Nagin. His defense did little to challenge their stories, Fanning said.
"It was too painful actually to watch. They just swamped him," he said. And when Nagin took the stand in his own defense, "He did a belly flop," often answering questions on cross-examination by saying he couldn't recall who paid for a trip or perk.
"He just looked terrible," Fanning said.
The earliest of the charges date from before Katrina, which struck when Nagin had been in office for about three years. The hurricane flooded more than three-fourths of low-lying New Orleans and left more than 1,800 dead across the region -- most of them in Louisiana.
Supporters credited Nagin's sometimes-profane demands for aid from Washington with helping reveal the botched federal response to the storm -- a fiasco that embarrassed the George W. Bush administration and led to billions of federal dollars being poured into Gulf Coast reconstruction efforts.
But Nagin also had his detractors: Fanning called his performance during the storm "a meltdown," a congressional committee criticized him for delaying evacuation orders, and his frantic description of post-storm New Orleans as a violent wasteland with up to 10,000 dead turned out to be greatly exaggerated.
As he sought re-election in 2006, with much of the city's African-American population displaced by storm damage, Nagin was blasted for insisting that New Orleans would remain a "chocolate" city.
"I have given my pound of flesh," he said.
Nagin sought to have the charges dismissed in October after another federal judge blasted what he called the "grotesque" misconduct of prosecutors in the post-Katrina shootings of unarmed civilians by police at the Danziger Bridge.
The judge tossed out the convictions of five cashiered cops after ruling that members of the U.S. attorney's office tainted their 2011 trial by anonymously posting "egregious and inflammatory" comments at online news sites.
Nagin argued that he was the target of the same underground effort, citing "a continuum of pejorative statements and demeaning racial epithets" aimed at him. The U.S. attorney's office said none of the prosecutors involved in the Danziger Bridge case played a role in the Nagin investigation.