> the cherry picked example of CA
California by itself accounts for more than 10% of the electorate and it's not a cherry picked example, it's what generally happens when a state is under one-party control. I provided links for California and New York because they're the two largest blue states by population.
> overrepresention of Republicans
That is what tends to happen in ungerrymandered districts because of the population distribution. Urban areas lean heavily for Democrats whereas suburban areas have a small Republican advantage, so if you draw ordinary natural district boundaries you end up with a smaller number of safe Democratic urban districts and a larger number of tight suburban districts that lean slightly red. To get something else you have to draw meandering lines that try to rope slices of the urban population into the same districts as the suburbs.
And yet, in the last decade no party has had more seats in Congress without getting more of the vote.
> this is from Citizens United
That was just the case that made it to the court, and it was pretty clearly correctly decided. The alternative is the government can prohibit you from distributing political speech because it costs money to do it, which would imply that they could ban all private mass media under the argument that there are some people who can't afford a printing press or a radio tower.
Or worse, tolerate corporate mass media and prohibit anything else, which was effectively the status quo before and the reason you see so much criticism of Citizens United from the legacy media.
Previously if you wanted to convince people of something you had to buy product advertising from a legacy media company to get enough financial leverage to pressure them to emit favorable media coverage, or buy them outright like with Comcast and MSNBC. Now that anyone can buy political advertising directly they have less need to indirectly bribe those media companies anymore and the media companies hate it. Meanwhile the actual effect is that you can now buy a political ad without having enough money to buy the network itself.