Nancy Reagan, Walter Mondale, Susan B. Anthony and Patty Hearst (machine gun in hand) showed up at the Source Theatre last night.

Well, sort of.

It was a Halloween benefit for the Source, and guests came as their favorite politician or member of the American electorate.

The Source's fundraiser turned into a victory celebration, when toward the end of the evening, word arrived that Source had won the battle to retain its current theater space on 14th Street. Cheers filled the house when Source finance director Henry Canaday announced that the theater would be able to keep the space an architectural and engineering consulting firm had sought to convert into offices. The Source, he said, has settled on a contract with an insurance company that will let it lease the building with an option to buy. Canaday praised Mayor Marion Barry and city business and economic development director Kwasi Holman for their help in solving the theater's housing problem.

Approximately 120 guests paid $50 each to dine on Popeye's Fried Chicken. Or perhaps it wasn't the chicken that lured people in. Mark Russell, Washington's favorite comedian, was promised.

And he delivered.

Although the bow-tied comedian took shots at everyone from yuppies to the Central Intelligence Agency, his favorite target was Ronald Reagan, whom he referred to as "the Teflon lame duck."

Russell broke into song frequently, pounding away at an old piano. To the tune of "Everything's Coming Up Roses," Russell sang his version of the State of the Union address: "Things look great/things look swell/though he's 73, what the hell . . . deficits climbing like roses."

Another tune that went over well was a CIA recruiting song. Before singing the song, Russell asked the audience rhetorically, "If it's a covert army, how do we all know about it?"

The song went: "We're going over/we won't come back till it's over/that's why I'm joining the covert army/we'll be returning Nicaragua to its former owner/like we did in Vietnam/we're going to make you just like we are/Ramada Inns and Pizza Huts in Managua/just like Saigon today . . ."

Doing a brilliant impression of Rod Serling, Russell created the scenario for a possible Twilight Zone segment. "Good evening, tonight we're going to meet a man named Ronald." The audience laughed heartily as Russell continued, describing a Ronald's world where a balanced-budget amendment worked. "Ronald lives in a world galaxies apart from ours."

The debates gave Russell plenty of mileage. He drove the audience wild with his "translations" of debatespeak.

"When George Bush said, 'Let me help you, Mrs. Ferraro' -- translation -- 'don't you worry your pretty little head about those things.' "

"And when Geraldine Ferraro said, 'I am here because Fritz had the courage' -- translation -- 'when the National Organization for Women lights a fire under a guy he gets courage real fast.' "

Although Russell took more jabs at Reagan, he didn't seemed impressed with either candidate. "The final debate was a draw. Why a draw? Because Mondale didn't whine and Reagan didn't stammer."