RECYCLED DOONESBURY: Second Thoughts on a Gilded Age by G. B. Trudeau (Andrews & McMeel: $12.95) . Reading this large-format anthology makes it easy to understand why Garry Trudeau was denied permission to join President George Bush's Thanksgiving visit to the American troops in the Middle East at the last minute. It's surprising that he was even considered for the trip, as Bush has long been the target for some of Trudeau's most vitriolic satire. During the '88 election campaign, he satirized Bush's lack of commitment to any guiding philosophy or principles by caricaturing him as a void wrapped in the American Flag. (He drew Michael Dukakis as an ineffectual pile of slung mud.) Other choice strips lampoon the tobacco industry's advertising and disinformation campaigns, the banalities of USA, various New Age fads (including a visit to some of Boopsie's earlier incarnations) and the opulent excesses of Donald Trump. The cartoonist reveals his kinder, gentler side in the bitterly funny cartoons about Joanie's old beau, Andy Lippincott, who must confront both AIDS and his parents' reaction to his diagnosis. Trudeau remains the only mainstream cartoonist to tackle this difficult subject, and these pointed strips attest to the talent that made him the first comic-strip artist to win the Pulitzer Prize for editorial cartooning.