Hillary would have broken 55% in 2008.
I don't think so--Obama's 1) more likeable, 2) more fresh in '08, and 3) didn't vote for the Iraq War. He was the better candidate in that election for sure.
Plus, his candidacy was objectively one of the best ever--he inspired "hope" and "change" and all that jazz like nobody's business--igniting the base and winning over moderates--and he was one of the first candidates to utilize modern technology to help him. This is how he beat Hillary in the primaries--an impressive feat, given that the pre-anointed establishment favorite is rarely ever beaten.
To pivot this back to the original question: if Obama couldn't do it, I'm not sure if anyone else can. It's too polarized nowadays--most people who vote in general elections seem to just robotically vote for one party or the other.
I felt Hillary would have won Missouri, Arkansas, West Virginia, and only lost Indiana and North Carolina