Hawaii has relied on federal prosecutors to expose widespread official corruption that’s tarnished the state and all four counties, with local law enforcers contributing little to cleaning out the rot.

This critical layer of protection could be lost if the U.S. Supreme Court continues its path of limiting the authority of federal prosecutors in local corruption cases.

It’s compelling reason to light a fire under Hawaii’s attorney general to join the fight and give the office tools it needs, starting with recommendations of a legislative panel working to raise ethical standards.

As reported by Politico, the Supreme Court is increasingly skeptical of using federal law to police local corruption, striking down a bribery conviction of former Virginia Gov. Bob McDonnell in 2016 and fraud convictions of New Jersey Gov. Chris Christie’s allies in 2020.

Two weeks ago justices seemed equally dubious in questioning attorneys about a corruption case involving developers tied to former New York Gov. Andrew Cuomo.

A comment by Justice Clarence Thomas went to the heart of Hawaii’s problem: “What is curious about this case is that the state of New York doesn’t seem to be upset about this arrangement. It seems as though we are using a federal law to impose ethical standards on state activity.”

It could similarly be argued the state of Hawaii — at least as represented by its attorney general — didn’t seem upset that two state legislators accepted cash and casino chips to derail legislation for a cesspool executive, or that county regulators accepted bribes to OK permits, or that a former Honolulu police chief and his prosecutor wife used their offices to commit fraud.

A commission appointed by House Speaker Scott Saiki to suggest improved standards of conduct proposed tighter ethics, lobbying and campaign finance laws, as well as giving Hawaii enforcers more tools to fight corruption such as fraud statutes used by federal prosecutors.

These would clearly help, but the problem may be more in little motivation of local enforcers to attack graft.

The attorney general, appointed by the governor and confirmed by the state Senate, is a creature of the political system the office is supposed to police.

Former Attorney General Margery Bronster, who investigated corrupt trustees of Kamehameha Schools/Bishop Estate, was voted down by the Senate for a second term at the behest of powerful trustees, one of whom was a former Senate president.

Perhaps it’s time to bolster the attorney general’s independence by making the office elected and nonpartisan, as the counties do with their prosecuting attorneys to varying success.

Former Honolulu Prosecutor Charles Marsland delighted in poking elected officials and prosecutors on Oahu, the Big Island and Maui who earned enough voter trust that they went on to be elected mayor.

On the other hand, former Honolulu Prosecutor Keith Kaneshiro was himself neck-deep in corruption allegations and awaits trial on his own federal charges.

There’s no easy answer, but one sure thing is that a culture of integrity is seldom achieved when it depends on enforcers biting the hands that feed them.

Reach David Shapiro at volcanicash@gmail.com.