With a new cloud over his presidential campaign, Republican Herman Cain plans a three-stop Ohio swing that could test the impact of the latest allegation of inappropriate behavior. The former pizza executive planned to begin Wednesday with a rally in a GOP-dominated area of southwest Ohio in West Chester, head to Dayton for a rally, then go on to Ohio State University. Cain told aides on Tuesday he would keep up his immediate campaign plans while assessing how supporters are reacting. He denies a Georgia woman's claim they had an extramarital affair over 13 years. Cain had jumped to the top of the GOP field in the key swing state of Ohio in a late October poll by Quinnipiac University. But he has been sliding since in national polling.