Are you a liberal? Are you a conservative? A libertarian? Left or right? Are you an anarcho-capitalist? Are you an anarcho-communist? An anarcho-syndicalist? Do you think government ought to be structured as a republic or as a direct democracy? These are all questions about people’s political ideologies. We typically individuate or distinguish between these ideologies according to a system of two independent axes that aims to pick out spectra of independent ideological positions, one economic and the other having to do with authority. There are problems with this view. For example, ideologies about political economies and the use/abuse of political authority are not neatly separable into independent spectra. Obviously, your views about if and when the state can justifiably use force to extract money from its citizenry to finance its policies will be influenced by your economic views and your views about political morality.
Opposed to this view of the political landscape is the horseshoe theory, which was developed by Jean-Pierre Faye. Horseshoe theorists view the political landscape as a single spectrum which bends like a horseshoe. As one reaches either end of the horseshoe, one approaches the extremist versions of left or right wing political ideologies. The point of this is that the left and right wings, as they go further left or right, end up converging such that the political spectrum becomes a horseshoe. While they don’t completely touch, they resemble each other enough to be more like their left or right wing extremist rivals than the centrists occupying the curved portion of the shoe. So, in essence, as left wingers and right wingers get more left wing and right wing, respectively, they end up resembling their ideological opposition on the opposite end more and more.
The problem I see with this view is that it conflates the contents of a political ideology with the tactics for implementing those contents that are seen as permissible by the proponents of those ideologies. So, a defender of horseshoe theory will point to how extremist right wingers and extremist left wingers are both willing to use violence as a means to the end of implementing their political ideologies into the social order. This is problematic, because we should individuate political ideologies based on their contents rather than the tactics contingently endorsed by their proponents. There are proponents of political ideologies who would typically not be classified as extremist who would be willing to use violence or tactics usually ascribed to extremists. The question is what the morally salient conditions are for justified uses of violence, and that is a question answered by the contents of particular political ideologies. So, ultimately we need to look to the contents rather than the tactics when individuating political ideologies.
Now, the horseshoe theorist may push back and claim that when we consider the so-called extremist left and right, their ideologies have quite similar standards by which violence or other extreme tactics are morally justified. The problem with this reply is that it’s outright false. It takes just a few minutes to look up so-called extremist left and right wing ideologies’ views about the justified and unjustified use of extreme tactics, and once you do that you’ll see that they differ significantly with respect to the reasons that they deploy to justify the use of tactics that the horseshoe theorist thinks makes them so similar.
So, while I don’t endorse the dual axis view of the political landscape, it’s clearly better as a tool for individuating contemporary political ideologies than the horseshoe theory.