The presidential race has entered a new realm: search-engine optimization, the art of polishing one’s image in cyberspace by manipulating Google & Co. to promote friendly Web pages (such as a campaign’s official site) and bury negative ones. “Politicians are looking for something known as ‘reputation management,’ ” says Gillian Muessig, who runs a Seattle-based optimization company called SEOmoz. Earlier this year, Muessig says her firm was contacted by a fellow cyber-marketer who was doing work for Rudy Giuliani’s campaign and offered her a cut of the business. She declined. “It’s frightening to think that one could sway the future of the free world by toying with who gets to the top of search engines,” she says. A Giuliani spokeswoman says she’s unaware of any effort to hire search-engine-optimization firms.