So far this campaign season, Fred Thompson has gotten ahead by standing off to the side. The other racers get tired, they get beaten up by the road, and he doesn't. That all ends tomorrow night in Dearborn, Michigan, when Thompson joins the Republican field for the first time. (According to news reports, during his rehearsals, former New York Sen. Alfonse D'Amato has played Rudy Giuliani. Doesn't Thompson know better actors from his time around sets?) Playing catch-up may well work to Thompson's advantage, since no clear and unproblematic frontrunner has emerged. Of course, there's also a chance that he will be derided by the other candidates as a Johnny come lately.