That means that Gov. Bobby Jindal, who opposes the suit, may soon be able to replace the supporter on the Southeast Louisiana Flood Protection Authority-East.
The decision will likely indicate whether a series of such lawsuits filed by Plaquemines and Jefferson parishes will be tried in state court or federal court.
Jindal delayed signing the bill earlier this week to wait for Caldwell's opinion, but the governor is not heeding the attorney general's advice to dismiss the legislation.