system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does the Left-wing of US Politics tend to still be very right-wing and conservative in comparison to European political parties (including the UK even tho it's not a part of the EU)
gpt
Communism. No, seriously.

Remember that Communism started in Europe. Marx and Engels were European. They wrote for a European audience. Communism took root very strongly in Europe, much more strongly than it ever did in the United States.

In Russia, it led to a revolution. In the rest of Europe, governments pulled farther to the left to appease the Communist sympathizers in their countries and (hopefully) avoid what happened to Russia.

That planted the seeds for it. Then you had World War II, the bloodiest battle in the history of the world. Germany had almost 10% of its population killed, and in Poland it was closer to 20%. Europe was devastated economically, morally, physically.

In the aftermath of WWII, the causes of which were complex but many of which had a lot to do with Right Wing nationalism, Europe pulled to the left, eager to avoid ever having a war like that again.

At the end of the day, the Europeans discovered that being that far to the left wasn't necessarily a bad thing. Europe has an older population (due to declining birth rates), and so a strong social safety net for the elderly was considered a boon. Socialized medicine is more efficient by practically every metric. They do some things wrong, but they do some things right. The United States tends to feel that if things are done differently from how the US does it, it's "wrong", even when that's demonstrably not the case.

Another, harder-to-quantify difference was the urban/rural/frontier split between the United States and Europe. For centuries, Europeans had relatively centralized states and were used to dealing with the government. In the United States, there were still frontiers (the Wild West, etc) and the government was often a distant entity that the average person didn't interact with as much. This fomented a distrust of government and statism in the United States among portions of the population.