It took Rome a long time to completely fall apart. There were bad emperors who hastened the process, and good emperors who almost pulled things back together. Kerry (or Gore, or the Clintons) are in the "bad emperor" category. Nero fiddled while Rome burned. Monica s**ked while Clinton I mishandled military and foreign policy.
I suppose Kerry wouldn't kill the country entirely, but he'd sure give it the old college try.