Less than five minutes into last night's presidential debate, John McCain started talking about a man he called "Joe the Plumber," who didn't think he would benefit from Barack Obama's tax plan. And Kevin Heron, a senior at McDaniel College, began scrawling on his bingo card. He was among 50 students playing "Debate Fallacy Bingo" - a game devised by McDaniel professors to show how the candidates' arguments often fail basic tests of logic. Each student had a bingo card, and each box contained a type of logical fallacy. Heron wrote "Joe the Plumber" in the box marked, "Appeal to...