LAKELAND, Fla., Sept. 15 — At his second campaign stop of the day on Friday, just after 2 p.m., Fred D. Thompson was deep into a riff on the benefits of high-quality American health care. “It’s allowing us to live healthier lives and to live longer,” Mr. Thompson said at a Jaycee park here. “That’s good news. But we have more retired folks. I hope to become one of them one of these days.” Nervous laughter from the audience. “Not too soon,” he added hastily. So much for dispelling the idea that he is too lazy to run for president......