EXETER, N.H. (AP) — Mitt Romney is on cruise control as his Republican presidential rivals struggle to overcome personal and campaign woes.Romney hasn't taken questions from voters in 10 days. Instead, the former Massachusetts governor has been raising money and positioning his campaign for a general election clash against President Barack Obama. He has yet to run his first television ad.The low-profile strategy is possible largely because of his opponents' problems.Herman Cain is facing another charge of an unwanted sexual advance. Texas Gov. Rick Perry is explaining quirky campaign trail behavior. Other candidates are struggling to keep staff and raise money.Phyllis Woods, a New Hampshire-based National Republican Committee member, says that Romney is both lucky and smart.___Elliott reported from Iowa.