IRVINE — The most famous line to emerge from the Watergate hearings was: "What did the President know, and when did he know it?"

In "Mastergate: A Play on Words," Larry Gelbart's scathing lampoon of the Iran-Contra scandal, it becomes: "What did the President know, and does he have any idea that he knew it?"

The satirical gulf between those lines is not only funny but also a measure of the perceived difference between the Machiavellian plotting of a Richard M. Nixon and the Panglossian bumbling of a Ronald Reagan.

Further, it represents the modus operandi of a sendup in which Gelbart, who helped create the TV series "MASH," takes his "MASH" sensibility to a Capitol Hill hearing room and savages all sorts of dimwitted political creatures. They have no less trouble crippling the language with a fusillade of imbecilic euphemisms and dopey evasions than they do corrupting Washington.

As staged by Dudley Knight at UC Irvine, moreover, the Southland premiere of "Mastergate" is more than just a revival of a 1989 comedy taking us down memory lane. It is a spectacular theatrical happening, a vibrant farce that revels in pop reality.

The production buzzes with excitement from the moment you cross the threshold of the metal detectors flanking Jeffrey Hall's all-encompassing set. You take your seat on the stage amid scores of players in the hearing room itself, which is dominated by half a dozen TV monitors as well as a huge early-American painting of George Washington and the Founding Fathers. And you feel as if you're part of the show, a witness to some hilariously absurd history that sounds ridiculous but very much like the truth.

Various governmental operatives testify about being "non-participants" in "non-meetings" and "non-discussions" involving Mastergate Pictures Inc., a Hollywood studio allegedly used to launder money for covert military aid to right-wing guerrillas in Central America through the making of a big-budget action film called "Tet: The Movie."

Maj. Manley Battle, "America's only four-star major," concedes the movie's budget mushroomed from $40 million to $1.3 billion "with the catering." But nobody was the wiser, he claims. Even the President didn't know anything about the covert operation. Just how does Manley know that? Because "I was told the President didn't know." And who told Manley, who has so many medals that his lawyer is wearing some of them? "The same people who told (the President) that he didn't know."