She will take the same demographics albeit at lower quantities.
The Democrat share of the youth vote, in particular, will be much lower than Obama. I expect this to be the main difference. A lot of this group will vote third party (Stein or Johnson), stay home, and a small but notable percentage will vote Trump. This is the "Bernie or bust" demographic. Most voted Obama both times (for those who were old enough), many are new to politics (voting age or got interested because of Bernie or Trump), but a ton of these voters of these will not vote Clinton.
I also expect Clinton to have a lower African American turnout and share of the vote overall than Obama. I think this is widely agreed on. This will be a slight shift away from her, but significant overall in shear numbers of votes.
I do however, expect Clinton to maintain or beat Obama with Hispanics with Trump on the ticket, albeit not by much in terms of share and turnout. This won't matter anywhere, however, except in Florida.
Overall, I am expecting a nail biter election. The Obama coalition is weaker for Clinton, and Trump voters are excited to vote for Trump. Given the D/R gap in previous elections, and the enthusiasm Trump creates and lack thereof for Hillary, I expect the gap to shrink significantly.
I think you're massively underestimating this.
