Well, socialism is good on paper, but in real life it doesn't and can't work. Humans are too greedy and selfish and they will always want more money/power. It is in human nature. We can't change human nature. Socialism also kills incentives. Economy needs growth and I don't think that socialism can provide growth/jobs.
Throughout history socialism has always been engrained in human society. From Sparta to Sweden, from Norway to Naples, socialism played a vital role in shaping western society. It's the sociopaths like thatcher who don't believe in such a thing as society and the psychopaths like libertarians who believe in plutocracy that go against human nature.
As for socialism being a failure, I'm glad my taxes pay for our NHS, I'm glad my taxes pay to protect the poor, I'm glad my taxes pay for state education at all levels of society, I'm glad to support my country and to work with my fellow citizens to make this country a better place for all. Socialism a failure? It isn't socialism that results in homelessness, nor starvation, nor the financial crisis, nor deaths from preventable illnesses, it's capitalists who are the cause of that, and these are the things conservatives are conserving.
As America grew, social programs were started to try to stop the ills of a growing nation, but they have only compounded them. As our society continues to grow and programs are expanded, we are finding more people are utilizing these programs than are not. Eventually, apathy will overtake ambition and the social systems will crumble. I have a Master's degree and I see that, in certain states, it pays more to be on social systems than for me to work a 40+ hours workweek... How is this "fair and just" in people's eyes? We do have a moral obligation to care for those who cannot care for themselves, children, disabled, the elderly who are unable to work, and animals, but there is no such obligation to able-bodied adults. We merely need to provide them with the equal opportunity to be productive members of the economy. Freedom of school choice for inner city children to attend better schools, merit-based scholarships to college, easier access to student loans/grants, and removing names from resumes to prevent discrimination in hiring. Once equal opportunity has been provided, there is no blame, but on the individual.
Notice that I said pure socialism. There are very few places in the world that have what would be considered a "pure socialistic" form of economy. Also there will be very few places that you can find "purely free markets." From history we have learned that an economy focused purely on redistribution and an economy focused purely on competition can be equally damaging. (e.G. Russia for the past 100 years and America's "robber barons" respectively) From an economical standpoint, it seems that the best growth results from right of center economic policies. However, we still need regulation so we can't lean too far right.
Horizontal power structures don't work and can't work, and this is a result of human nature. As humans, we desire not just the ability to strive and prosper but leaders. This can be seen everywhere in other animals/mammals that form groups (societies). In the case of humanity, this isn't a biological need, but a psychological one. It has a lot to do with the need/expectation of trust in others.
The current systems deployed (Socialism, Communism, and Capitalism) all work best in smaller populations. With the global populations of various countries easily breaking millions strong they all bend and break in different ways under the weight of the population itself. Socialism fails because it cannot function in a system with complex needs; most people list off the basics for human survival in socialist propaganda but for modern needs things like transportation, technology, and so forth and so on begin to have extremely detrimental responses when applied to socialist thought.
Socialism is not natural. Prior to the population boom across the globe for humans you usually had smaller and more tribal systems that don't resemble any of the modern three systems at all because they worked essentially like technocracies.
The most basic and oldest human unit regards community is the tribe. Tribes survive by taking care of each other and remaining essentially equal economically. So to say that socialism is contrary to human nature is incredibly naive. There's a reason that the happiest people even today are tribal peoples. And that the happiest nations are socialistic, Denmark being tops in both happiness and commitment to socialism.
Capitalism did not exist when America was founded. The term was created by Karl Marx, who coined it in his manifesto.
Before Marx, Americans didn't have terminology to create rhetoric out of. The right wing didn't have a buzzword they could demonize.
Anyway, America has and always will be a nation with a socialist/capitalist hybrid economy. Because that economic system was the best option at the time, and likely still is.
The demonization of socialism from right wingers is indicative of their lack of economic and historic perspective.
Socialism is not against human nature. Human nature shouldn't be confused with the basis of a civilization. Basic human nature pushed us to live in small economic units where resources were shared equally in prehistoric times. That is essentially the definition of stateless communism / socialism, the final goal, is it not? We, in Western Society, have oppressed human nature with the idea of property ownership and capitalism, and since we are so used to it (as we are taught it from childhood), we think of it as "human nature", which is false. There are examples of civilizations who were more socialistic. Take the Inca, for example. Their civilization followed a more socialist model in which a certain percentage of goods produced were to be given to the state to be redistributed to those who were less fortunate. Socialism is not against human nature, only the western way of life.
I think that Socialism and Capitalism will merge together one day to form some sort of hybrid economy wich would get the best of both systems.
I imagine something similar to the scandinavian social-democratic model.
Maybe we could introduce a basic income for all so that nobody has to live in poverty.
Is it against human nature?
Is it doomed to fail?
Before capitalism was popular a lot of countries have socialist economies. However the key thing is that laziness is also part of human nature. If a country has successfully had a socialist economy for a long time, they might not want to subject to change(as this may potentially yield more risk than reward). The more modern western countries usually operate on a mix between socialist and capitalist system as before the Industrial revolution they were mostly socialist. So in the end, yes it is against human nature, but laziness cancels out greed so it isn't doomed to fail.
How is it against human nature?
Socialism, like any other policy, will fail due to human nature, as some people will not pull their weight, and human nature will cause exploitation and anger from this inequity.
This is no different than capitalism failing because some people are greedy, while others are left behind for various reasons.