Kentucky’s Supreme Court on Thursday delved into another legal fight between the state’s Democratic governor and Republican-led legislature — whether individual lawmakers are shielded from being named as defendants when the executive branch sues to challenge legislative actions.

The question is an outgrowth of Gov. Andy Beshear’s court battle against GOP-backed legislation limiting his emergency powers during the COVID-19 pandemic. The governor named state Senate President Robert Stivers and House Speaker David Osborne as defendants in the suit.

The top two legislative leaders filed a motion to be dismissed from the suit, arguing they were covered by immunity as legislators. A Franklin County Circuit judge denied their motion and Stivers and Osborne appealed, ultimately sending the case to the state’s highest court.

Both sides presented their arguments during a Supreme Court hearing Thursday.

An attorney for the Republican lawmakers said the state’s Constitution “unambiguously protects members of the legislature from being attacked in court for the bills that they enact.”

“Separation of powers would be distorted beyond recognition if executive officials could open a second front in the legislative process by attacking members of the General Assembly in court for the bills that they enact,” the attorney, Paul Salamanca, told the justices.

During rounds of questioning from the justices, Deputy Chief Justice Lisabeth T. Hughes expressed respect for legislative immunity, calling it “a very important doctrine.” Hughes added that the governor’s legal team seemed to be arguing for “a very narrow exception to legislative immunity — not all-out susceptibility, if you will, to sue.”

“There are exceptions to judicial immunity, and I think this is what’s being argued here is an exception to legislative immunity,” she said.

Travis Mayo, the governor’s general counsel, cited prior court rulings holding that legislative immunity “is not an absolute shield” when legislation is being challenged.

“This is one of those cases where legislative immunity does not apply,” he told the court.

Mayo also warned that broad application of legislative immunity could leave the executive branch with no legal recourse when attempting to challenge the constitutionality of legislative actions.

If the legislative leaders and the state’s attorney general had been dismissed as defendants in the current case, Mayo said, the governor “would have been left with no defendant to challenge the constitutionality of these laws and would have been left with no redress.”

The case is an outgrowth of a larger separation-of-powers fight over coronavirus policies.

Kentucky’s Supreme Court, in a landmark 2021 ruling, cleared the way for new laws to rein in the governor’s emergency powers in combating the spread of COVID-19. One of the contested laws limits the governor’s executive orders in times of emergency to 30 days unless extended by lawmakers.