He won a Pulitzer Prize in 2001 for his investigative reporting in The New York Times. His new book is Perfectly Legal: The Covert Campaign to Rig Our Tax System to Benefit the Super Rich — and Cheat Everybody Else. Johnston was hired by the Times to cover taxes and he approached it like an ongoing investigation. In his new book he writes, "I was especially surprised to find that some of the biggest tax breaks for the rich are not even in the tax code, and that the IRS was completely unaware of many widely used tax fraud schemes. But what surprised me more than anything was the realization that our tax system now levies the poor, the middle class and even the upper middle class to subsidize the rich."