Interface by Neal Stephenson and J. Frederick George

There's no way William A. Cozzano can lose the upcoming presidential election. He's a likable midwestern governor with one insidious advantage—an advantage provided by a shadowy group of backers. A biochip implanted in his head hardwires him to a computerized polling system. The mood of the electorate is channeled directly into his brain. Forget issues. Forget policy. Cozzano is more than the perfect candidate. He's a special effect.