I'd agree that calling the Dems and GOP "left and right" is somewhat meaningless but historically the left-right spectrum was originally about "power to the peo

I'd agree that calling the Dems and GOP "left and right" is somewhat meaningless but historically the left-right spectrum was originally about "power to the people" vs "power to the king" and has been generalized to "hierarchies bad" vs "hierarchies good". Of course this is a spectrum because there are many dimensions in which politics can be "left" or "right" (e.g. social norms, welfare, spending, policing, regulations). The problem with the Democrats and the Republicans isn't that they're two coherent parties. They're both parent organizations for state-level parties which can be politically extremely different from each other. And those parties can themselves be ideologically incoherent because people join them simply because there is no point in joining a third party instead, not to mention that in some cases in-party election (e.g. the primaries) allow non-members to vote, which further messes with their political coherence. And don't even get me started on how PACs and big donors affect campaigning.