European countries tend to be more open to Socialist government, despite having been largely supported against the Socialist states in the latter half of the twentieth century by the US. Is there any specific historical reason as to why this seems to be so?

A lot of ink has been spilled trying to answer the question: why no socialism in the United States? The question was most famously asked over a hundred years ago by Werner sombart.

There are a lot of answers:

The two party system Economic growth Americas diversity State repression Cultural

Eric foner wrote a relatively famous essay on the topic in the 1980s if you're interested I believe it's called "why is there no socialism in the US"

Another book that explores the repression of the left is robin dg kelley' hammer and hoe

Part of me though, wants to answer that there is and has been socialism in America. However, it's contributions have largely been erased whether through the celebration of Samuel Gompers over Clara lemlich or the forgetting of Paul roberson. In all honesty, the McCarthy trials are a much nicer version of anti-radicalism than what came before