The problem with Presidential elections is small rural states still have outsize influence via the combination of more EC votes than a population-based count AND winner-take-all elections (51% of the vote in. A state and you get 100% of that states electors) in most states.
Turn there’s the Senate. Because it’s not based on population, CA and TX have the same influence as SD and DE. Combine that with arcane super-majority rules and a defective filibuster and it’s a recipe for outright obstruction by the minority party.