Why income inequality threatens the Republican Party

Via Andrew Gelman and Avi Feller, we have the following chart showing the election results for four income groups (based on exit polls. Blanks indicate states that were not polled).

I'll let Andrew and Avi explain the results above

Lower-income voters consistently support the Democratic candidate in nearly every state. Upper-income voters, on the other hand, are more mixed in their political views: wealthy voters in Mississippi are strongly Republican while wealthy voters in Massachusetts are strongly Democratic.

And now to the threatening part. Consider the following

• The median income in the US is $50K. Translation? Half the voters in the country are going to - overwhelmingly - support Democrats
• As inequality grows, the percentage of people in the >$100K will decrease. Translation? The number of people who might vote Republican will decrease

 And that is a problem, and a significant one at that.  To quote Danny DeVito in "Other People's Money",  "[Y]ou know the surest way to go broke? Keep getting an increasing share of a shrinking market."
Turns out that inequality isn't just something that the bleeding-heart liberals need to worry about, its something that should keep Republicans up at night too, unless they want to follow the buggy-whip manufacturers into oblivion...