"The study period covered five presidential elections from 2000 (673 Democratic counties, 132 833 397 population; 2439 Republican counties, n=147 957 141) to 2019 (490 Democratic counties, n=176 971 611; 2622 Republican counties, n=145 413 920) (supplementary tables 1 and 2)."
This is also happening at the state level, and is causing the Senate to become ridiculously radical. It only takes the support of 5.1% of US voters to filibuster a bill, and 12% to defeat a filibuster:
https://www.reddit.com/r/politics/comments/2jnmbe/i_did_the_...
The "supervoters" making up that 5.1% and 12% are mostly in Republican states, and this has led to the Republican party drifting farther and farther right of the mainstream over time. For example:
74% of Americans want action on climate change: https://www.pewresearch.org/fact-tank/2021/09/14/americans-a...
69% of Americans want to keep Roe v Wade: https://www.marketwatch.com/story/what-percentage-of-america...
Yet neither can get 50 votes in the Senate, let alone the 60 required to pass.
democrat 143 counties, n=91 809 974 to 156 counties, n=133 796 619 And republican 292 counties, n=61 407 202 to 280 counties, n=46 244 883
So overall health is improving, but it is improving more when increasing sample size. It is normalized, but still different things are compared.
Thanks I didn't know all that about democrats and counties, seems more involved then I thought.