The Louisiana Supreme Court on Tuesday heard former state legislator and convicted felon Derrick Shepherd’s argument that the constitutional provision that disqualified him from running for the state House of Representatives this fall is invalid.

The court could rule on the question next month.

Shepherd is hoping the high court agrees with a Baton Rouge judge who ruled in September that a discrepancy between the wording of a constitutional amendment passed by the Legislature and the language on the ballot measure later approved by voters renders the provision invalid. It said convicted felons could not run for office for 15 years after the end of their sentence.

The amendment approved by voters in 1997 did not include a last-minute change by the Legislature that exempted felons who were sentenced only to probation, and Shepherd argues there is clear legal precedent to throw out the law as invalid, even though the omitted provision would not have applied to him.

Shepherd, who served two years in prison after pleading guilty in 2008 to public corruption charges, filed to run for the District 87 seat in the House this year, but his candidacy was quickly challenged. His two-pronged legal battle was unable to keep him in the race, which was ultimately won by Rodney Lyons Sr.

A Baton Rouge judge agreed with Shepherd on the constitutional question, but the decision was appealed by the state to the Supreme Court, resulting in Tuesday’s hearing.

In the meantime, the state filed a separate case in Jefferson Parish to disqualify Shepherd under the terms of the constitutional provision. He lost that case at a trial and before the state 5th Circuit Court of Appeal, keeping him off the Oct. 24 ballot.

His attorney, Robert Garrity, tried to get both courts hearing that challenge to consider the constitutional question, but neither did.

Follow Chad Calder on Twitter, @Chad_Calder.