IN A RARE MOMENT of consensus, liberals and conservatives passed and subsequently praised the Tax Reform Act of 1986 and the move toward a flat income tax that lies at its heart. The reform “flattened” the tax code not only in the sense that it reduced the number of tax brackets and the differences between them; it also sought to eliminate distortions of behavior produced by special tax breaks and loopholes. The consensus that emerged included the newly rediscovered conviction that the tax code should strive simply to collect revenue rather than to reward or encourage certain types of financial or social behavior.