Why do Americans accept an economic system that is unfavourable to the majority of them?

The majority of Americans reject more generous social welfare and an increase in the tax burden. Yet a majority of Americans suffer from the low generosity and the cost of the healthcare system, the crumbling infrastructure, the low skills of a large proportion of the labour force, the high levels of inequality and poverty, and the low levels of social mobility. The low level of social mobility should counter the argument that Americans accept these difficulties because their children will be better off than they are.