Obama warns of more attacks to come

Democrat Barack Obama held onto his solid lead in the polls and appeared confident of capturing the US presidency in the historic race, but steeled his supporters for a crescendo of vicious attacks in the final hours of the campaign. With just four days to go after a marathon contests, the Obama campaign went on the offensive in several solidly Republican states Friday. Democrats announced they would air television ads in Georgia, North Dakota and even Arizona, which Republican John McCain has represented in the US Senate for 22 years. "We are four days away from bringing change to America," Obama told a crowd in Iowa, where he won an upset victory in January in the state's presidential caucuses. "Four days." The underdog McCain, meanwhile, spent a second day touring Ohio in his "Straight Talk Express" bus, and appeared with California Gov. Arnold Schwarzenegger, a fellow Republican, in a last-ditch effort to win a state critical to his hopes for victory.