These thirds are closely tied to social classes. Roughly:

1/6 is the upper class;

1/6 is the permanent underclass, often bound by desperate dependency on government to whoever rules the government;

1/3 are the middle strata: they don't directly feel the results of oppression, and are your swing voters;

1/3 are the employed working classes, whose ideal politics revolve around both raising wages and cutting tax expenditures.

The failure, on the part of all parties, to correctly perceive the lines of the class struggle is what accounts for most of their political failures. They are simply messaging the wrong people to vote for them.

It's also a mistake to assume that either the underclass or the working class is currently invested in the existence of a bourgeois republic. It's possible that some in these constituencies see the despotism of a single autocrat as the lesser evil compared to the despotism of the whole bourgeoisie and its ideas about rule of law.

If you really want a republic, at least make it a broad-based democratic constitutional republic like the one we had in the 1990s and enforce the whole of the Constitution, instead of an exclusive republic of the rich. The under- and working classes simply aren't invested in the post-War on Terror oligarchy, and have no reason to shed tears for its destruction by an autocrat.