Former St. Gabriel Mayor George Grace Sr. has failed to convince a federal appellate court that a 20-year prison term for public corruption is unreasonable for a man in his early 70s.

Grace was convicted in 2012 of racketeering, bribery, fraud, obstruction of justice and making false statements to federal agents — all charges stemming from an FBI sting operation involving a fictitious garbage can cleaning service called Cifer 5000.

He was originally sentenced to 22 years behind bars, but U.S. District Judge S. Maurice Hicks Jr. cut two years from that in 2014 after the 5th U.S. Circuit Court of Appeals ordered a recalculation of the projected monetary losses to the federal government and private investors.

In challenging his new sentence, the 71-year-old Grace argues, among other things, that the prison term is not reasonable for a nonviolent first-time offender and is effectively a life sentence for him.

“The district court heard Grace’s arguments for a lesser sentence based on his age and other factors but determined that a 240-month sentence, which the district court noted was lower than Grace’s original sentence and a substantial downward variance from his guidelines range of life imprisonment, was appropriate,” a three-judge 5th Circuit panel wrote Thursday.

“Grace has not shown that the district court abused its discretion in regard to his sentence,” the panel added.

The federal sting operation, known as Operation Blighted Officials, also led to the convictions of former New Roads Mayor Tommy Nelson Jr., ex-White Castle Mayor Maurice Brown, former Port Allen Mayor Derek Lewis and other area municipal officials.

The 5th Circuit last month let stand Nelson’s 10-year prison term.

Brown also is serving 10 years. Lewis was sentenced to 40 months.