Beginning with the Kennedy administration’s Ideological Organizations Project, which investigated, intimidated, and challenged the tax-exempt status of right-wing foundations, Mr. Andrew traces the ways Democrats and Republicans alike used the IRS to accomplish political goals during the 1960s and early 1970s. Seemingly innocuous names like Operation Leprechaun and Project Tradewinds, together with an array of intelligence and surveillance activities, formed a pattern of abuse that threatened the foundations of American political culture. In one of the most powerful and sobering passages of the book, Mr. Andrew chronicles the IRS’s Special Service Staff, which carried out activities that were more extensive and intrusive than Nixon’s infamous Enemies List—yet received scant coverage in the media.