The question, why has there been no socialism in this country, addresses American exceptionalism. Why is the United States the only industrialized nation that never had an electorally viable socialist or labor party? Every other developed country has had one to one degree or another. The fact that the U.S. has not means that it is different from other countries.
Yes, the National Socialist Movement in the United States is preventing harmonious relationships in the country. The National Socialist Movement is listed as a hate group by the Southern Poverty Law Center. The group's neo-Nazi ideology is divisive - anti-Jewish, racist, and anti-immigrant - and its goals are specifically to disrupt equality in the U.S.
Obviously they are not helping, but such groups tend to unify America and push us to be better then the people running them if anything. Its just such a shunned thing in this country, and I don't even feel a hint of fear from its existence. I know those types of people are out there, and always will be. Honestly I'd rather have them out in the open then planning things in secret.
No, the National Socialist Movement in the United States is not preventing harmonious relationships in the country. The only one preventing harmonious relationships is Donald Trump. The electoral system is broken, and voters have decided to nominate a man with zero experience to the head of a major party. This is what hurts the country.
Simply put, there aren't enough people in the National Socialist Movement to affect anything in the country. Although I find them a little bit repulsive, it's America and you can think what you want. I don't see a future in which the socialists gain any real traction in America, especially after the nightmare that Venezuela is going through.
One in five Americans insists the sun revolves around the earth and it isn't the fault of the National Socialist Movement or the KKK or whoever. Its a cultural thing with, for example, the preachers of the Southern Baptist church causing a mass exodus among their own congregations when they started competing to see who could come up with the most vitriolic sermons.
In fact, I know people who go to such meetings just to rant and rave and spout total crap. Its to the advantage of those with money if they can keep people fighting among themselves and, for example, Rupert Murdoch, owner of Fox News, has made a fortune off selling them all the crap they can swallow. When two of his own reporters refused to lie on the air about an egregious public health issue they were fired. Hollywood movies glorify whistleblowers, but the sad truth is nobody wants to hear the truth and the US has virtually no protection for them.