The US spends more on healthcare -- measured in total, and per capita, and as share of GDP -- than any other OECD country, even though it and Mexico are the only OECD countries without universal healthcare. It spends more out of public funds on healthcare (again, by all three measures) than many OECD countries providing universal healthcare spend in total, while also spending more in private spending on healthcare than it does in public spending.
While the US spending about as much (a while ago it was a little more, right now I think its a hair less) as the rest of the world combined in military spending may be argued to limit resources for other activities, it is manifestly not meaningfully constraining health care spending.
The second is a misunderstanding of the concept of a republic. Each state has a say. That's not unfair. It certainly wouldn't promote stability for heavily populated cities to have complete control and entire states neglected.
Not sure I completely disagree on military spending. Like most things, it's a balance. We probably needed a rebalance (was done in the gov shutdown deal). However, I'm not sure it needs further cuts. Maybe just better focus.
Healthcare is a joke. What was passed, and the way it was passed, was deceitful. Turns out it was snake oil. Made some things better, made more things worse, and didn't fix the problem (cost of healthcare).
From a politics perspective, it sure would be nice to have a leader that brings people together. This administration is far to willing to leverage our political differences as a tool for political gain. That has made us culturally worse by creating an environment of distrust, disregard, and division Among our citizens just for having different ideas.
From my perspective, there's no one answer, but I've noticed a handful of things:
* Race - Most democratic socialist countries tend to have more homogeneous populations. The U.S. has sizable African-American and Latino-American minorities, often segregated into their own neighborhoods, and that often informs how the white majority votes -- i.e. things like welfare and prison reform are viewed as handouts to people not like themselves. You might say it's comparable to how perceptions of Greek laziness inform German attitudes towards debt cancellation.
* Geography - The U.S.'s political system grants a disproportionate power to sparsely populated states (e.g. a state like Wyoming has more electoral votes per person than California, and states like Iowa and New Hampshire have a large say in how the presidential primaries turn out). This matters with respect to policies that might be considered urban-centric -- e.g. public transportation.
* Militarism - The U.S. is the only country that regularly projects force halfway around the globe, and it's super expensive. Every dollar spent on bombs is a dollar not spent on healthcare. It's a good question as to why American voters constantly favor military might, but it's not necessarily an irrational choice. Or rather, you could argue that it wasn't an irrational choice during WW2 and the Cold War, but that the development of a military-industrial complex has had lasting effects on American politics.