Look who's a divider now: The experiment: A college professor wears a Kerry-Edwards shirt to a rally for President Bush, then a Bush for President shirt to a John Kerry rally. Result: Bush people make the subject remove his shirt, then give him the boot. The Kerry people don't make a peep. . .He had a ticket to an afternoon Bush rally July 31 in Cambridge, Ohio. At the first ring of security, Prather says he was told to turn his Kerry shirt inside out. He did. At the second ring, he was told to remove the shirt. He did, then donned a soccer T-shirt. "I was in for 10 or 15 minutes," he recalls, when security escorted him out. It was before the president arrived. "I was so far away I couldn't have even heckled him," Prather notes. A few hours later, he entered the Kerry rally, in Wheeling, wearing his Bush shirt. "Nobody said anything to me. "