The strip of M Street between Connecticut and New Hampshire Avenues has been one of Washington's liveliest areas after dark for quite a while now. So it's only natural that a political satire revue would spring up there.

Responding to this call of nature, "The Slightly Raucous Caucus" now inhabits the dining room of the Metropolitan Hotel, 1143 New Hampshire NW, for two shows nightly on Fridays and Saturdays.

Nature is not always nice, and "A Slightly Raucous Caucus" has a surprisingly formidable task. Sure, people here are fascinated by politics and government. Precisely because there are so many people in Washington involved in that sore of thing. We are surrounded by political jokes already. If it's not the joking of amateurs around the water cooler, it's Art Buchwald and Russell and Mark Russell and "Saturday Night" and the "National Lampoon" and even Johnny Carson. Not to mention the comedy of so many real events.

After a week of such stuff, paying for most of it may seem excessive. In order to attract customers, "The Slightly Raucous Caucus" should be excessive or extravagant or outrageous itself. It should be more than slightly raucous.

It is not. There are bright spots - debates between Rosalynn and Lillian Carter for First Lady, a fund-raising drive for the Pentagon, a futurist vision in which the Air and Space Museum is "the last repository of air and space," a cleverly visualized "bureaucracy machine." "David Susskind" is hauled before congressional committee investigating boring people and charged with "crossing interstate lines to attend a Smith Bagley party." A few non-political targets are thrown in - Georgetown parking, Bloomingdale's, the Metro. Nixon is rehashed.

The four performers, assisted by two instrumentalists, are attractive. But nothing is sustained very well, nothing packs a wallop.The last skit's last punchline hardly merits a smile. The show's labored title is all to descriptive of its content.