Not sure if this has been posted, but the
most exhaustive autopsy of 2024 was finally released.
Tl;dr:
Harris basically did slightly worse with every single demographic group than Biden 2020, except college educated women.
Turnout and support drops were mitigated in the battleground states (vs. safe states) which may have contributed to Trump's popular vote victory (he charged turnout in red states while blue states saw huge drop offs in support). This suggests that the campaigning in those states
did make a difference.
Young voters, especially young men, shifted hard to right across all demographics.
Voters of color in general shifted to the right across all age groups and demographics as well.
Irregular voters (i.e. people who voted in only 1 or two of the last 6 elections) were won decisively by Trump.