Pew came out with a new report recently on Party ID, they publish these every few years and other than Gallup are one of the main sources for data on Party ID,
https://www.people-press.org/2020/06/02/in-changing-u-s-electorate-race-and-education-remain-stark-dividing-lines/The main findings are these, total party ID in 2018/19 was 29% R, 33% D, and 34% I. If you include leaners, it was 44R, 49D, so a +5D balance among US RV's This is fairly consistent with previous years.
What struck me and why I think people talking about a religious Left are simply wrong is the pace of secularisation among the democratic party, increasingly among Christians, virtually every Christian denomination is becoming more Republican, hence the left is secularising extremely rapidly.
The share of voters who lean or identify as Democrats who are Christian has fallen from 73% in 2008 to just 52% by 2019, a huge fall in just 11 years, among Republicans the decline has been from 87% to 79%.
Among white non-evangelical Protestants for example, so basically mainline White Protestants, the R vs D split in Party ID was 45-45 in 2008, by 2012 it was 52-41, +11R and is now 54-39, +15R.
Among White evangelicals, the split in 2008 was 64R-28D or +36R, by 2012 it was 71R-22D, +49R, and is now 78R-17D, +61R.
Among White Catholics the shift has been from 41-49, +8D to 57-38, +19R.
Among white Evangelicals, the R share is the highest on record.
Among unaffiliated however the Republicans have lost ground, going from 25-64 in 2008 or -39D to 24-67 now, -43D.
There has been no shift among Hispanic Catholics.
So overall, religious groups on average have become more Republican whereas unaffiliated voters have become somewhat more democratic. So the religious gap has continued to grow.
There are other findings on Party ID by age and gender which one could write a lot about, about how Gen X men are now quite different from Gen X women etc.
