2. President Franklin Roosevelt (D)
President Roosevelt used the IRS against a host of political rivals and business opponents, ranging from populist Sen. Huey Long (D) of Louisiana, United Mine Workers leader John Lewis, Rep. Hamilton Fish (R) of New York, Chicago Tribune publisher Robert "Colonel" McCormick, Philadelphia Inquirer publisher Moses Annenberg (a fierce opponent of the New Deal), and, most famously, former Treasury Secretary Andrew Mellon.
The Roosevelt administration focused the IRS and an army of tax inspectors and prosecutors on Mellon's financial records, especially whether deductions for his vast philanthropic activities amounted to tax evasion. Even after IRS agents found nothing irregular, the Justice Department pursued the investigation. Historians have found no documents explaining the Roosevelt administration's focus on Mellon, but a comment Roosevelt made about him in 1926 may offer a clue: Roosevelt dubbed him "the master mind among the malefactors of great wealth."
A federal grand jury declined to indict Mellon for tax fraud in 1934. But the IRS was still pursuing claims against Mellon for at least $3 million in back taxes. Mellon's storied "tax trial" before the Board of Tax Appeals in Pittsburgh and Washington lasted 14 months. At a private meeting with Roosevelt during the trial in 1936, Mellon offered to build the National Gallery and endow it with his own collection. Roosevelt accepted the offer, but instructed federal prosecutors to make "no change whatsoever" in the government's position on the Mellon tax case, according to Mellon biographer David Cannadine. Mellon died the next year, and the suits, including any against his estate, died with him.
"Although Richard Nixon was notorious for treating the I.R.S. as though it were his private domain, the records show that Franklin Delano Roosevelt may have set the stage for the use of the tax agency for political purposes by most subsequent Presidents," writes former New York Times reporter David Burnham, author of "A Law Unto Itself: Power, Politics, and the IRS."