By Patricia Wilson NANTUCKET, Mass. (Reuters) - Democrat John Kerry (news - web sites) hit back at Dick Cheney (news - web sites) on Thursday by raising the Republican's failure to serve in the Vietnam War and asking voters to weigh his two tours of duty against the vice president's five deferments. Kerry, a decorated Vietnam War veteran, bristled at Cheney's attack on his patriotism during the Republican National Convention in New York and his ability to serve as U.S. commander-in-chief. "Here's my answer," the Massachusetts senator said in excerpts of remarks he will make at a midnight rally in...