“The problem with this line of thinking is that it fails to take the candidates into account.”
Yes. Had a better candidate run, the Republicans probably would have won FL, OH, VA, and CO in 2012. I think that would have put anyone but Romney over the top :-). All 4 of those states were within 2% of Der Fuerher if I am not mistaken.
You also have to remember that was a huge black voter turnout that did not show up in 2010 or 2014, The Dems aren’t going to get the same numbers they got without Obama to tap into the black vote.