The conspicuous trait uniting Hiss's dogged ex-post-facto bloodhounds with his die-hard defenders is the need to be 100% right in order to vindicate not only their verdict on American history but the governmental policies they espouse today.
The right-wing line goes something like this: liberals were wrong about Stalinism in the thirties; wrong about the influence of domestic communists; wrong about the Vietnam War; and wrong, wrong, wrong about the strength of the Soviet threat. And so it stands to reason that liberals must be wrong today in their opposition to the war in Irak and the erosion of civil liberties associated with the war on terror. Once a naïve liberal, always a naïve liberal.
On the left, the reluctance to let go of the Hiss case also has a pedigree extending from the 1930's: the right was wrong about the threat of Nazism and dismissive of the role played by Soviet Russia in holing off the Germans until America entered the war; wrong about the righteousness of the hunt for domestic Communists in the late forties and fifties; wrong about Vietnam; wrong about Gorbachev's sincere desire for reform; and wrong about the staying power of both communist ideology and the Soviet empire. Finally, of course, liberals believe that the right is wrong about the Irak war and wrong in its willingness to sacrifice some of our own cherished civil liberties in order to fight terrorism.
For both groups, the guilt or innocence of Alger Hiss remains today what it was in the fifties — a symbolic and real indicator of which side you were, and are, on.