Okay, I know he's a liberal (Exh. 1: "The Conscience of a Liberal"), and so am I, so there are times when I suppose Paul Krugman's arguments seem irresistible when they're not. But today's column strikes me as just plain common-sensical.Krugman offers up four common excuses often used to argue against health reform and then refutes them. It is worth a read. Here are the excuses:Excuse No. 1: No