When Reagan Met Gorbachev

Friedersdorf has a few questions for Andy McCarthy:

In instances too numerous to list, American Presidents have usefully “worked with” people and regimes of the most despicable sort. FDR worked with Joseph Stalin. The very same Joseph Stalin who purged millions of his own people, took a stance of paranoid aggression against Western countries, and subscribed to an ideology literally bent on world domination. Despite being one of the biggest moral monsters of recorded history, there were times when the interests of his regime overlapped with the interests of the United States.

What explains this bizarre tendency on the American right to talk as though the primary job of an American president is to identify malign regimes and political factions, insult their leaders, and never speak to them under any circumstances?