If there ever was a political honeymoon for Gov. Jon Corzine, it appears to be over. In his first four months in office, the Democrat has proposed an increase in the sales tax and broken a promise to give homeowners dramatic relief from the highest property taxes in the nation. Corzine's approval ratings have sunk, and fellow Democrats in the Legislature are hesitant to back his budget plan."He did a great job as senator. You would just figure it would carry over as governor," said disappointed Democrat Neil Harry Lori, a plumber from Montclair who liked Corzine's liberal record in the Senate, especially his 2002 vote against authorizing President Bush to invade Iraq.