Political, ideological, demographic and economic trends are all leading toward durable Democratic majorities in Congress, control of most statehouses and, very possibly, the end of the decades-old GOP hammerlock on the electoral college.
Trouble with the social "sciences" is that you can pretty much say anything, then look later for a small piece of data that proves you right. I think every time a party loses an election we hear all sorts of competing reasons, but one usually catches on more than the others with the popular press. Not out of any intrinsic value, but just because people seem to like it. This year will prove no different. I'm sure you can find at least one article that will blame a GOP presidential loss on the phenomenon you mention. Then again, the GOP may end their own "decades-old hammerlock." The winning formula has won them seven of the last ten elections, but they're not playing by that book just now. They're not rallying around a candidate, and no one is consistently leading in primary polls. No doubt you'll be able to find at least one article expounding on that as the reason for the defeat.
Of course if the republicans win, you'll have lots to choose from by way of explaining how the Democrats let it "slip away" from them. Gotta love the "social sciences." Nobody's ever wrong.
