What do you get when you combine the secret corporate conspiracies of “The X-Files” with the populist outrage of “Erin Brockovich”? Something resembling “Bill Moyers Reports: Trading Democracy” (9 p.m., PBS, check local listings).

Remember all of the fuss about NAFTA? Back in 1992, Ross Perot promised us that there would be a “giant sucking sound” that represented all of the American jobs heading towards Mexico. While NAFTA opponents like Perot focused on the threat to American jobs, few politicians or journalists seemed to be reading the fine print. According to Moyers, the NAFTA agreement contains a clause called “Chapter 11.” Originally included to protect corporations from having their assets seized by foreign governments, the proviso has been used by foreign companies to sue local American governments, and force them to change laws or jury decisions that might harm their bottom line.

Moyers cites the case of Methanex, a Canadian company that produced an ingredient in the gasoline-additive MBTE. California residents became alarmed when they discovered MBTE, a known carcinogen, in their groundwater. The California legislature responded in 1999, and ordered that the additive be phased out of the state’s gasoline. Using the NAFTA clause, Methanex sued the state of California for $970 million in compensation for loss of business and future profits.

Journalist William Greider sums up the opposition to this legal maneuver. “If Methanex wins its billion-dollar claim over California environmental law, there ain’t gonna be many states enacting that law, are there?” Greider adds, “Governments are already being intimidated by the mere threat of a claim being filed against some regulatory action.”

And who gets to decide the validity of Methanex’s claims? This is where “Trading Democracy” begins to sound the “The X-Files.” Moyers explains that all hearings related to Chapter 11 suits are heard at a secret tribunal at the World Bank in Washington. No outside citizens, journalists or elected officials are invited to these.

While Moyers, co-producer Sherry Jones and Greider make a moving case here, it should be noted that no one from Methanex would comment, and the NAFTA tribunal is ominously represented by microphones around an empty table. All the same, “Trading Democracy” raises an issue that deserves further examination.

l Tonight on “Frasier” (8 p.m., NBC): It took Niles the better part of a decade to confess his love for Daphne. So, don’t expect things to go smoothly when the fussy perfectionist plans the perfect way to pop the question.

l “Out of the Closet, Off the Screen: The Life of William Haines” (9 p.m., AMC) examines the now-forgotten career of a Hollywood individualist. One of the leading stars of the silent era, Haines refused to hide his homosexuality, and found himself blacklisted by the MGM studio. He channeled his creativity into new directions, and became one of the most sought after interior decorators and furniture designers of his day.

Tonight’s other highlights

l At a charity auction, Jess outbids Dean for a chance to date Rory on “Gilmore Girls” (7 p.m., WB).

l “Secret, Lies and Atomic Spies” on “NOVA” (7 p.m., PBS, check local listings) revisits one of the greatest code-breaking efforts of the 20th century, the successful decryption of the Soviets’ spy code. It also explores why some uncovered spies were never prosecuted by American authorities.

l Nick’s visiting revives painful memories of his mother’s death on “The Guardian” (8 p.m., CBS)

l Jack goes on the lam on “24” (8 p.m., Fox).

l A woman who shares explicit stories with her children is accused of being an unfit mother on “Judging Amy” (9 p.m., CBS).