For those interested in the relevant history that lead the US to this point, may I suggest American Character by Colin Woodard [1].

The ideology that drives the oligarchy (and arguably modern libertarianism) is descended from that which informed the founding of the Carolina and West Indian slave colonies.

[1] http://www.amazon.com/American-Character-History-Struggle-In...

Colin Woodard's previous book, American Nations was the most interesting book I read last year.