Let's posit that conservatives have every reason for optimism in the coming elections. The Tea Parties are enthusiastic and powerful. Middle America is fed up with big government. The left is dispirited. The polls looks great. It therefore would take a real wet blanket to warn that the momentum could fizzle and the triumph be less than grand. Sorry, but this blanket is wet indeed. Before we go any farther, please understand: This is not a prediction; it's a warning.