You made a very bold assertion about massive population movement in the US. I just asked for any sort of data at all to back that up. A very fair question before anybody wastes time on any discussion with it.
Hold on.
First off, in a thread about retaining the Senate, I said 50-50 is likely, and I meant to say 52R-48D but I tried to use parallel ratios and mixed up the letters. Which I corrected. I can see the Senate being 48-52 either way. Who knows? No one until the votes are counted.
So, this entire thread is "feelings".
Second, you bolded me saying: "
The more concerning thing is that as the population shifts from rural areas to regional cities"
This is happening now, and it's always been happening. You can look at census data throughout US history to see regional cities literally attracting people from rural areas to regional centers where there are jobs and opportunities that just don't exist in rural areas.
As regional cities grow, attracting more open-minded liberal-esque people, rural states are going to become more red. And as we all know, no matter how small of a population North Dakota has, they get 2 Senators. And no matter how large of a population California has, they get 2 Senators.
I didn't predict a massive population shift. I'm talking about the ongoing population growth of regional cities/megaregions over 20-30 years.
In the future, 20-30 years from now, the House will be one thing, while the Senate will be another. Unless the Senate is apportioned by population, I highly doubt that traditional conservatives won't have a solid majority, if not super majority. At least with 50 states. Adding states would change that, which is why Republicans are so against it and liberals are relatively behind it.
Again, unless you think that regional cities and megaregions are going to start dispersing liberal voters into rural areas. I think that's a far more unlikely scenario.