It seems like since at least 1930's, the left wing in America is much weaker than in most other countries, to the point of almost not existing in the mainstream. The party most Americans consider left wing would likely be seen as centrist or right of center in most other countries, at least compared to the popular left wing parties elsewhere. There isn't a large socialist party, or a large social democrat party in the political mainstream. It seems like the whole of the American political spectrum for the two large parties starts off as further on the right of the spectrum then most other political parties in other liberal democracies. I'm aware that there are some left wing parties and movements, but from casual observers standpoint they seem to be either fringe movements, or have no official representation in the major parties, barring the occasional charismatic figure that pops up every once in a while(Bernie Sanders and the like).

Is it entirely because of cold war propaganda, or are there more complex factors at play? (I really hope there are more complex factors at play that someone can describe to me in detail!)

Edit: I've also noticed that working class Americans tend to gravitate towards the right end of the political spectrum (economically), while where I come from the working class gravitates towards the left end of the spectrum(economically). Is this phenomenon unique to the United States, and if so, are there traceable historical and social causes for this? Thank you!