The U.S. spends more on medical care, per citizen, than almost any other nation.

For a government program you have to be elderly or disabled in order to get on (and which the capitalist class-supporting bureaucrats have been trying to turn into a private stock market racket for over a decade now, mind you), or which (in the case of Medicaid) it's extremely difficult to get on since millions of people are making just enough to be ineligible for it but not making enough to buy private insurance, so that are uninsured. That is not the case in nations that are social democratic, and health insurance (single-payer or otherwise) wouldn't be needed at all in a true Marxian system. The U.S. spends so much on just Medicare and Medicaid compared to other nations because these other First World nations do not spend such a disproportionate amount of money on the military and periodic bail-outs.

The U.S. spends more on education, per student, than almost any other nation.

Yet we charge an arm and a leg for college tuition, and private elementary and high schools are quite popular here. College debt--with debt being a regular feature of capitalism--is skyrocketing in the U.S., and has been for three decades now. The U.K., which also has a student debt problem, nevertheless only allows universities to charge the equivalent of $14,000 annually (no doubt horrifying to Libertarians that there aren't a few individuals in the U.K. being allowed to grow too obscenely rich by bleeding the students completely dry via debt), while the German government completely funds its college students (no doubt doubly horrifying to the Libertarians, so no few individuals are able to bleed college students dry to any degree in order to get rich). These other countries also entirely finance their students' college education: Argentina, Denmark, Greece, Kenya, Morocco, Egypt, Uruguay, Scotland and Turkey. Some of these aren't even First World countries. So it would be interesting to know where all the money the U.S. government spends on education actually goes into.

The U.S. spends a good deal on other social programs, too.

Not since the infamous Clinton Welfare Reform Act of 1994. And not since New Deal benefits have been gradually eroded over the past few decades.

If other wealthy nations spend less on defense, it is because the U.S. is paying on their behalf.

In exchange for U.S. military bases and a continued U.S. military presence over there, and all so these countries remain friendly to U.S. business interests. The government doesn't do anything with no strings, as that doesn't happen under the current system.

For pretty much every ethnic group, Americans live longer, are healthier, are better educated and make more money than that same ethnic group in their home country.

Not according to readily available stats, such as this and this regarding health and longevity (and these sources are hardly known for liberal politics!); this and this regarding education level and cost (again, hardly progressive sources!); or in regards to having a better standard of living monetary wise, according to this when you take actual spending ability of income into account rather than just raw sum of money earned (something conservative sources fail to do for obvious reasons).

The problem is NOT that the U.S. spends too little. The U.S. has a lot of problems, but that is not one of them.

Clearly, how much it spends in every single area is far less important than what it actually spends the money on, and how much in proportion to other nations actually goes to benefit working class people.