By TERI SFORZA

In the years since Robert MacLean followed his gut instinct about doing the right thing, life has become unrecognizable.

Fired from his job as a federal air marshal. Branded a threat to public safety. Unable to get work in his chosen field of law enforcement.

He moved his family into Mom’s house; filed for bankruptcy; and now watches wearily and resignedly and amazedly as his fate settles onto the black-robed shoulders of the U.S. Supreme Court’s nine esteemed justices.

Somehow, life has become a chess game. Which he’s playing against the federal government. And Uncle Sam always seems to have two queens to his one. Can he possibly win?

For a time last year, it seemed like he could. After years of defeats, the U.S. Court of Appeals threw out earlier decisions against him, and commanded lower officials to concentrate on whether MacLean had a legitimate fear that the public could be harmed when he did what he did. Was MacLean, indeed, a whistleblower? Did he endanger the flying public, or protect it?

His former bosses at the Department of Homeland Security didn’t much like that. They asked the Supreme Court to step in and consider the security issues MacLean’s case raises; and on Monday, the Supreme Court said yes.

Briefs are to be filed by September; oral arguments are expected in the fall, with a decision before the court adjourns next year.

A blow for MacLean, of Ladera Ranch.

It’s not good when you win in a lower court and then the Supreme Court decides to take the case, said Erwin Chemerinsky, dean of UC Irvine’s School of Law, by email. “But the Court taking it really just reflects that they see an important issue of law to resolve. It is a significant case,” he said.

What government secrets must a federal employee keep, even if he foresees terrible danger on the horizon?

MacLean is getting his chess pieces in order: Joining longtime attorney Tom Devine of the Government Accountability Project is Neal Kumar Katyal, President Barack Obama’s former acting solicitor general. Katyal, as luck would have it, replaced Solicitor General Elena Kagan when Obama appointed her to the, er, Supreme Court.

HERO OR VILLAIN?

MacLean was a nuclear weapons maintenance technician for the Air Force from 1988 to 1992; he earned several ribbons and medals. Then he joined the U.S. Border Patrol and worked for almost six years, until 9/11 happened. He followed his gut then, too, joining the swiftly expanding ranks of air marshals swept into service to make the skies safer. His was the first air marshal class to graduate after the 9/11 attacks, trained in investigative techniques, criminal terrorist behavior recognition, firearms proficiency, aircraft-specific tactics and close quarters self-defense measures.

All went smoothly until 2003, when MacLean received an alarming emergency alert from the Department of Homeland Security, detailing a “specific and imminent terrorist threat focused on long-distance flights – a more ambitious, broader-scale version of the 9/11 plot,” court paperwork says. “Every air marshal, including MacLean, was given an unprecedented face-to-face briefing about the threat. MacLean and the other marshals were informed about special measures being implemented to thwart the attack and were told to be especially on their guard.”

So imagine MacLean’s alarm when, within 48 hours of the secret briefing, he got an unencrypted text message from the Transportation Security Administration scrapping all overnight missions and instructing air marshals to cancel hotel reservations immediately so the government wouldn’t be charged cancellation fees. The text message was not marked as sensitive information; it was not encrypted; and it was sent to MacLean’s unsecured cellphone, not to the secure personal digital assistant that the TSA had provided for transmission of “sensitive security information,” or “SSI” in bureaucracy-speak.

This, thought MacLean, was crazy. The 9/11 hijackers targeted long-distance flights because they could do the most damage. Pulling air marshals from such flights, precisely when there was warning of a possible attack, was gross mismanagement – and a “specific threat to public safety that could lead to catastrophic loss of life,” he’d later argue in court papers.

MacLean protested to his bosses. Then to their bosses. When he got nowhere, he finally told a reporter for MSNBC.

Fallout was fast and furious. Lawmakers – including Hillary Clinton and John Kerry – decried the idea as foolish. Officials backtracked, and, ultimately, overnight missions continued as per usual.