This article from Harvard Magazine asks why inequality of income distribution and life expectancy is so much greater in the U.S. than in other countries with a similar GDP.
Unequal America: Causes and consequences of the wide—and growing—gap between rich and poor, by Elizabeth Gudrais.
The author comes to no clear conclusions as to either the causes (historical? ideological? accidental?) or the possible remedies, but she gives us material to work with to come up with our own. Some of the proposed remedies, including stricter rules on campaign financing (so the favor-the-rich candidates don't get all the money), sound like timid steps in the right direction. A movement mobilizing greater numbers of the poor and non-poor to vote seems to me like the best way to change laws on who gets the tax breaks, which neighborhoods and which institutions get public funds, and so on. And that's the big reason for backing Obama, who is the only one currently able to motivate those folks on a national scale. (Not to slight Kucinich and others, who are working to do the same thing but whose reach is narrower.)