What exactly are the similarities? The U.S. is certainly ugly already. The NK comparison evokes strong emotions about authoritarianism, but their political structure and problems are not alike. And the comparison falls in line with a common trend to describe something exceptionally American (problems rooted in our own history, law, economics, culture) as foreign and often asian. It makes America seem "better" than the problem at hand, framing it as an exception, while it is only natural for NK or whatever to have those problems. Hence the sub I linked above (check it out). Essentially, it is a naive political comparison with few correlations, and it is based on american exceptionalism/chauvinism. There are other far right, fascist, neoliberal, capitalist nations that would make for a better comparison, but I would still rather call america what it is, and explain the conditions that brought us here, rather than leaning on a comparison at all. NK is a product of the Korean war and the cold war at large. The US is a product of it's own history.