Why not mention "polarization"? If you have data for congress from 60's to now, you can take the max value from the scree plot as a function of time. Perhaps that's leading to a hypothesis: polarization of the voting spectrum drives loss of nuance in political opinion space. That seems straightforward to prove from a maths point of view, but is likely more difficult to even support at a sociological level.

It would also be interesting to see what else two-party-based political polarization could drive, or at least strongly correlate with. For example, here's another hypothesis: Once the spectrum of law-making is divided into mutual antagonism between left and right, the process of law-enforcement will follow suit by adapting jurisprudence to harsh persecution more often than to lenient forgiveness (never mind the now-forgotten maxims "innocent until proven guilty" and "cruel and unusual punishment", the cancel culture and the mob mentality have both done away with all of that "useless antiquarian thought"!).

There's probably not enough good data about politics and trials during the French revolution, but there are a few well known cautionary tales, the worst one I know is about Antoine Lavoisier who--in addition to being a humanitarian scientist--was guillotined one year and completely exonerated the next.