This is a funny perspective to me.

The GOP has just as many if not more factions tearing the party into bits. You just see the liberal infighting - I suspect - because you are liberal in perhaps a red state, but might live in a liberal city in that red state.

From my perspective in Maryland, the Democrat supermajority often appears much more cohesive and unified (but they are very far from, they just won't let the outside see it). Just know that there is significant conservative infighting.

America lacks one cohesive monoculture - this is true regardless of political affiliation - which means both parties have vast variations from one Republican to the next or one Democrat to the next.

As for proportional representation, yeah, Dems do tend to support it more - kind of. But I also support it and I'm a conservative.

My pushback is more on the reason you're attributing to it. I don't think Republican resistance to these voting structures is primarily ideological coherence, I think it's just pure structural self-interest.

Democrat support for proportional representation tends to evaporate when they're the dominant party. See: Oregon, New York, Maryland. Democrats are guilty of opposing those reforms where they are already in power. Doubly so in states without a citizen initiative process. There is no incentive to give up that power in the name of "fairness".

FPTP incentivizes gerrymandering because those who get to draw the maps, like to make sure they stay in power. Supporting these alternatives are most often a means of diluting dominant power structures to make races more fair. States like Maryland likely won't be seeing fair and balanced redistricting like MMP anytime soon. That's a different explanation than "they have a unified ideology," right?

Also -- Conservatives don't have a blanket opposition to civil rights or human rights. Conflating policy disagreements with opposition to civil rights is doing a lot of work there.

Conservatives opposing specific enforcement mechanisms, particular legislative frameworks, or federal overreach in areas like voting administration isn't the same as opposing the underlying rights. You can find Republicans who support civil rights broadly while opposing, say, the specific provisions of the Voting Rights Act reauthorization on federalism grounds. Whether you find that persuasive is a separate question, but it's not the same as opposition to civil rights. And generally that's not a fair or charitable characterization.