It's a good point. In modern times, we know what the electoral college would look like in an R+2 victory to a D+8 victory, but if the margin goes all the way to D+15, we'd see some really weird results. Some states that we might otherwise assume to be safe R states would flip. And I do think it has a lot to do with the candidate too - for example, Obama would definitely win Montana and the Dakotas in this scenario, whereas Clinton wouldn't, but she'd very likely win Texas and South Carolina. And the same applies on the opposite side of the spectrum for Republicans too. I don't think it'll happen but I kind of want to see Clinton win by a margin like this just to see a crazy map.
If Obama were to win by 15 points, I think he would end up winning NY, CA, IL, MA,WA and other solid Democratic states by North Korea or Soviet like margins. He would still be radioactive in the Upper South and Appalachia. His EV margin wouldn't be impressive as if Hillary were to win by 15 points. Texas would flip this year if Hillary won by 15 points, but Texas was more than 15 points to the right of the nation in 08 and 2012.
