Finally, a liberal answer to the smug and smarmy P.J. O’Rourkeand a funnier one, too. Former Saturday Night Live scribe Al Franken leaps onto the pundit pile with his latest book, wonderfully titled Rush Limbaugh Is a Big Fat Idiot…and Other Observations. No mere opportunistic nonbook, Idiot refutes the Republican Revolution with actual facts and well-reasoned argumentsin addition to extensive gratuitous-but-funny Rush- and Newt-bashing (e.g., the index catalogs only fat references). A surprisingly smart volume, it will do little good against the rising tide of “didiots”as Franken calls dittoheadsbut one must try. Franken will scribble cheeky autographs tonight at 7 p.m. at Olsson’s, 1200 F St. NW. FREE. (202) 347-3686.