Advocate file photo by JOHN McCUSKER -- Former Jefferson Parish President Aaron Broussard arrives for sentencing in federal court in New Orleans in 2013. Broussard is trying to get his guilty verdict set aside based on prosecutorial misconduct.

An attorney for jailed former Jefferson Parish President Aaron Broussard made his case Tuesday that his client is entitled to a hearing with testimony from former U.S. Attorney Jim Letten and two of his former prosecutors concerning the online-commenting scandal that overturned one verdict and torpedoed another investigation.

But a three-judge panel of the 5th U.S. Circuit Court of Appeals repeatedly pressed attorney Arthur “Buddy” Lemann to say exactly how the comments made online by prosecutors — the vast majority of them about other cases — affected Broussard’s 2012 guilty plea to charges of conspiracy, wire fraud and theft related to a payroll fraud scheme and payoffs from a parish contractor.

Lemann argued that the comments were indicative of an inappropriate level of personal animosity toward the office’s targets. If Broussard had known the depth of the scandal at the time, Lemann said, it would have improved his bargaining power by making him “feel that the cards are not stacked against him.”

Counsel for the U.S. Attorney’s Office, however, told the panel that the comments had been public knowledge for as long as five months when Broussard entered his plea. In addition, government lawyers said, the comments were irrelevant to the facts in the case and should not cause a legitimate conviction to be thrown out.

Broussard, who is now serving a 46-month sentence in a Florida prison, asked a year ago for his guilty plea and conviction to be thrown out, but a federal district judge denied the claim in July.

Lemann told appellate judges Edward Prado, Jerry Smith and Priscilla Owen on Tuesday that Judge Hayden Head didn’t apply the appropriate legal standard to his client’s claim that Letten’s office prevented him from receiving effective counsel by not disclosing the extent of the scandal.

In that scandal, First Assistant U.S. Attorney Jan Mann and prosecutor Sal Perricone were found to have commented online about cases their office was pursuing, including the one against Broussard. Both prosecutors resigned — Perricone before Broussard pleaded guilty and Mann afterward — and Letten stepped down in late 2012.

The judges on Tuesday, however, were intent on finding instances where comments actually prejudiced the case against Broussard.

“Tell us how that directly impacted the guilty plea,” Owen said.

Prado asked Kevin Boitmann, a lawyer with the U.S. Attorney’s Office, whether anything about the indictment was ever disclosed online in anonymous comments, and Boitmann responded that no such instance has been found.

Boitmann said the legal standard for Broussard’s appeal is instances in which a person got very limited legal representation. He said Broussard’s attorney at the time got 25 of the charges in the corruption case against him thrown out, requested hearings and filed numerous challenges to the charges, making it very difficult to argue that Broussard did not get effective counsel.

Under questioning from Owen about how fuller disclosure might have affected sentencing, Boitmann said sentencing should be appropriate to the offenses to which a defendant pleads guilty and not mitigated because of unrelated conduct issues.

Lemann, however, dismissed the idea that prosecutors’ comments on other cases — including the later-dropped probe of River Birch landfill company owner Fred Heebe, who brought the online comments to light — were unrelated to Broussard’s case.

“I know in my heart of hearts that I could prove in an evidentiary hearing that the real target (in the Broussard case) was Fred Heebe,” he said.

It is not known when the appeals court panel will issue its decision.

The commenting scandal has been invoked by defendants in several other high-profile corruption cases, including Mayor Ray Nagin, former City Councilwoman Renee Gill Pratt and former city official Stacey Jackson, but to little effect.

The scandal did largely provide the rationale for a federal judge’s decision to vacate the convictions of five New Orleans police officers in the Danziger Bridge shootings and cover-up. An appeal of that decision is pending.

Follow Chad Calder on Twitter, @Chad_Calder.