A very high level of wealth inequality is unsustainable. Typically, the political problems only appear above .40 Gini coefficient, but policymakers can shoot themselves in the foot (e.g. when Pippi Longstocking's author Astrid Lindgren was sacked with a 110% tax rate, the poor woman was forced to question what Swedish tax policy had come to) even with relatively progressive and redistributive arrangements. In the case of countries with high wealth disparities such as Russia, China, the US and South Africa, the answer lies, as Putin's economic adviser noted, in "better crowd control." And sure enough, all of these countries do an excellent job. Indeed, when asked to describe how they perceive US wealth distribution, the model in most American heads looks much more like Sweden, which has a Gini of less than .30. The Occupy movement could talk and give data, but many people saw no problem. If you didn't have money, it was because of a lack of personal responsibility.
During the hydrocarbon and commodity windfalls of the early to mid-2000s, Russians forgave pretty much any other policy issues because suddenly everybody had money and could travel abroad. Similarly, having billionaires, even kleptocrats, was a matter of civil pride. Today, when that has not been working, the shift has been to a plain vanilla appeal to nationalist sentiment a la Rufus T. Firefly.
In the US case, it's hard to say, but I suspect somebody has already invented electronic Valium (Facebook? Cable news perhaps?). Benzodiazapine not only turns down the nervous excitement dial, it suppresses memory. As a result, many political discussions sound like memory-loss support groups.