After a review of information available to Truman about the presence of espionage activities in the U.S. government, Democratic Senator Daniel Patrick Moynihan concluded that Truman was "almost willfully obtuse" concerning the danger of American communism.[328] In 2010, historian Alonzo Hamby concluded that "Harry Truman remains a controversial president."[329] However, since leaving office, Truman has fared well in polls ranking the presidents. He has never been listed lower than ninth, and most recently was fifth in a C-SPAN poll in 2009.[330]
The fall of the Soviet Union in 1991 caused Truman advocates to claim vindication for Truman's decisions in the postwar period. According to Truman biographer Robert Dallek, "His contribution to victory in the cold war without a devastating nuclear conflict elevated him to the stature of a great or near-great president."[331] The 1992 publication of David McCollough's favorable biography of Truman further cemented the view of Truman as a highly regarded chief executive.[331] According to historian Daniel R. McCoy in his book on the Truman presidency,

Harry Truman himself gave a strong and far-from-incorrect impression of being a tough, concerned and direct leader.  