In the past, the U.S. has sometimes been described sardonically — but not inaccurately — as a one-party state: the business party, with two factions called Democrats and Republicans.
That is no longer true. The U.S. is still a one-party state, the business party. But it only has one faction: moderate Republicans, now called New Democrats (as the U.S. Congressional coalition styles itself).
There is still a Republican organization, but it long ago abandoned any pretense of being a normal parliamentary party. Conservative commentator Norman Ornstein of the American Enterprise Institute describes today's Republicans as "a radical insurgency — ideologically extreme, scornful of facts and compromise, dismissive of the legitimacy of its political opposition": a serious danger to the society.
The party is in lock-step service to the very rich and the corporate sector. Since votes cannot be obtained on that platform, the party has been compelled to mobilize sectors of the society that are extremist by world standards. Crazy is the new norm among Tea Party members and a host of others beyond the mainstream.
The Republican establishment and its business sponsors had expected to use them as a battering ram in the neoliberal assault against the population — to privatize, to deregulate and to limit government, while retaining those parts that serve wealth and power, like the military.
The Republican establishment has had some success, but now finds that it can no longer control its base, much to its dismay. The impact on American society thus becomes even more severe. A case in point: the virulent reaction against the Affordable Care Act and the near-shutdown of the government.