Biggest Flaw in the Democratic Party?

This is a problem that I often wonder about, but I don't know what the right answer to it is...

A big (main?) principle of the Democratic Party is to tax the rich to provide more help to the poor in our country, mostly for 2 reasons:
1. Utilitarianism: the poor can benefit more from an extra dollar than someone who is already rich. So it is viewed as an overall good thing to set up society such that the rich may not be able to afford as many vacations, but in return more people are able to have access to health care and education.
2. Fairness: your success in life isn't just a matter of hard work. Those who are born into wealthy families are much more likely to become wealthy themselves: access to better education, a safer environment to grow up in, less stress and therefore easier to do well in school, family connections in business, etc. So redistributing some degree of wealth is seen as making up for natural unfairness.

Obviously, Democrats would laugh at a proposed policy to raise taxes on those making over $250k just to give more to people who make $100k-250k. If the goal is to reduce the suffering of poverty and ease the worst cases of unfairness, obviously we should focus on those who actually need the most help.

With that in mind, how do the poor in America compare to third world countries? On a global scale, wanting to tax the upper classes of America to give more to the lower classes of America is a lot like the ridiculous case of welfare for people making $100k. From the utilitarian perspective, helping end malaria in third world countries does more good-per-dollar-spent than making sure every American has comprehensive health insurance. And when it comes to fairness: someone born in a poor part of America can complain that they didn't get a fair shot at success, but not compared to someone born in the Congo.

Democrats often accuse Republicans of failing to have a global perspective. But if your political philosophy is largely based around alleviating poverty/inequality, and your solution is to focus on increasing the social safety net of one of the richest countries in the world.... what would you call that?