Let's say in medium-term, every demographic is split 50-50 between D's & R's...

[Cashew]

We would have to *gasp* debate!

How? On what?

Everything is tainted by demographics. Trying to appeal to the rich or the middle class or the poor, this race or that one, male voters, female voters, trans voters, college-educated or less, urban or suburban or rural, etc.

Assuming all of that became irrelevant, people would still debate the environment, space colonization, liberty vs security, public health and other issues that are tainted by our current political coalitions.