Is it relevant what people do vote for?

Getting the most votes isn't what translates to forming a government in the US. The big things are: having your family members run state governments, setting district lines, and setting up laws to prevent people that disagree with you from voting. Not to mention just having a lot of money to bribe already elected politicians.

As an absolute leftist, I think you're overstating the effects of gerrymandering. State gerrymandering cannot win statewide seats, nor the electoral college.

Anti-voting regulations, while frankly absolutely despicable, I've not yet seen any studies regarding a significant effect. Do you have any data on that?

People do vote for these things, but if you split voters is a particular way you can ensure that the minority hold on to power (Gerrymandering and the Electoral College).

If you're looking at a 60/40 split though, even the extreme levels of gerrymandering can't override it. So what are the other things that people vote for - they must have a large rightward split if people keep voting right wing, in the face of all those left-leaning polls on policies.

That’s not how elections work in the US, 60/40 is not a big enough divide to undo a gerrymander. The majority of the liberal population lives in dense urban areas and thus their votes get “wasted” as they’re reliably Democrats, while sparser regions which consist of the minority view get more representation compared to their actual numbers.

Add to that the fact that many voters are single issue voters, so their opinions on different policies don’t end up amounting to much.

So even if some policies are popular overall, they need to be popular enough to overcome these things to form a durable coalition that advocates for them in the halls of power.