SAN FRANCISCO -- The three Republicans vying for the chance to unseat Sen. Barbara Boxer (D-Calif.) this fall were tripping over themselves yesterday in a rush to capitalize on momentum generated by a rare special-election upset in a liberal stronghold 3,000 miles away. Separate statements from the campaigns -- from former Rep. Tom Campbell, Assemblyman Chuck DeVore and former Hewlett Packard CEO Carly Fiorina -- had managed within hours to form a three-part swipe at Boxer, the chairwoman of the Senate Environment and Public Works Committee. Their message was this: Barbara Boxer, you're next. DeVore's version was typical. "This is...