The Kremlin is trying to rehabilitate Stalin, just like the wingnuts are doing with McCarthy

It's interesting to read that the Russian government is trying to polish Stalin's image.
For the past several years, some wingnuts have been trying to rewrite the history of Joe McCarthy's anti-communism, in order to suggest that he wasn't all that bad of a guy either.
Kind of ironic that the rewriting is happening on both ends of the political spectrum, from the communists to the anti-communists.
What do they hope to achieve?
It is troubling that either side feels that the black mark somehow hampers their efforts, as though they'd like to be more like Stalin, or McCarthy, if the public were just more amenable.