It's a situation most appellate counsel have faced: a client lost in the lower court, and there is a powerful argument for reversal that was not raised below. This is a problem, because appellate courts generally will not reverse based on an argument that was not presented in the lower court. And with good reason: Lower courts adjudicate issues in the first instance, and should be reversed only when they make a mistake in assessing what is presented to them. If the lower court was not given the chance to pass on the argument, it is hard to claim that it made a mistake.