Former Arizona congressman Sam Steiger, 53, a staunch conservative who gave up a safe Republican seat six years ago to run unsuccessfully for the Senate, has switched to the Libertarian Party to campaign for governor. His performance at the announcement indicated that the move put him in a good humor.

Why the switch? "I started getting all those Republican fund-raising letters," he quipped. "I figured this would be a good way to get off their mailing lists."

Does he expect to win? "Oh my God, no. Come on, be reasonable."

Was he worried about the assembled reporters' opinions? "I can finally tell you all to go shove it. I can't tell you how good that makes me feel."

Considering what's happened to him recently, the move should feel good. Steiger was convicted two months ago of speeding and using "abrasive and abusive" language to a highway patrolman. In 1975 he outraged animal lovers when he shot two wild burros, an endangered species, that were running on a neighbor's farm. Steiger contended that he shot in self-defense, that they attacked him. His critics wondered how it was, then, that the burros were wounded in the hindquarters.