From surface down to substance, Dick Cheney and John Edwards have their differences. This week they share one thing in common: they`ll be visiting Arkansas. Even though both running mates will be here to sway voters, their impact is doubtful. "Really, it`s the presidential candidate that ultimately matters," says Dr. Art English, UALR Professor of Political Science. But with a tight race expected, both parties say they need all the help they can get. Republicans are banking on Dick Cheney`s years of experience to help the ticket. Democrats hope John Edwards can convince Arkansas voters with his humble roots and story of "two Americas."