The thing about that cold-war sound-bite is that a typical dictator client of the USSR was often implementing some soviet-style policies. Why should America give benefits to one-party states without any strings attached? Should the principle of self-determination of nation-states be taken to mean "the nation-state is the one and only legal political party"? That sounds like a minor variation of "the state is me", famously asserted by a French aristocrat.
Typically, if a government either is designated as meriting most favored nation status for trade, or receives a stream of money paid by American taxpayers, then can we be confident that it's a government that at least...
- doesn't abridge the freedom of speech of its citizens
- doesn't interfere with the right of the people peaceably to assemble
- and doesn't prevent or punish the petitioning by citizens to their government for a redress of grievances?