I think the reason for Biden's low numbers is Propaganda 24/7 on talk radio and Fox. I think it works. I think the reasons for that success are that USians are a nation of people with low critical thinking skills, low public education (deliberate policy choices by GOP), and addicted for decades to media. John Perry Barlow once pointed out that TV is the mass hysteria making machine that takes the place of the medieval church, spouting falsehoods that people must believe - or die.
re: modeling approval w/polarization as a feature - how imbalanced is that metric? I'd think that most of the training data would come from low-polarized cycles (this Washington Post article has a pretty illustrative gif of just how recently house/prez vote shares have become correlated: https://www.washingtonpost.com/politics/2021/02/19/2020-saw-least-split-ticket-house-voting-decades/).
I think the reason for Biden's low numbers is Propaganda 24/7 on talk radio and Fox. I think it works. I think the reasons for that success are that USians are a nation of people with low critical thinking skills, low public education (deliberate policy choices by GOP), and addicted for decades to media. John Perry Barlow once pointed out that TV is the mass hysteria making machine that takes the place of the medieval church, spouting falsehoods that people must believe - or die.