The book was published in '90 and helped Bill Clinton win the '92 presidential election. I'll quote from this review to give you an idea of what it's about.
The Politics of Rich and Poor is a well-written, extensively documented, and easily understood portrayal of fundamental changes in the internal financial make-up and external standing of the United States due to political decisions made during the Reagan years. Phillips has provided both hard data and anecdotal evidence to confirm what many may not know or have perhaps only suspected. Internally, wealth has become more and more concentrated at the upper end of the economic spectrum, especially for the wealthiest one percent or so of U.S. taxpayers, while middle and lower income Americans now hold a much smaller share of the nation's total wealth. Externally, the United States has become a net debtor nation for the first time since World War I and has first mortgaged, then sold large amounts of the nation's assets to foreign investors. The net effect is that for most measures of wealth from the individual level (say, the number of billionaires per capita relative to total population) to the international level (like international bank assets) the United States has surrendered its position of economic leadership while decreasing the economic opportunities of most of its own citizens.And wealth has continued to concentrate up until today, where levels of income inequality are now estimated by economist Emmanuel Saez to be greater than at anytime in the history of the nation.