So would I be wrong in saying that the polls should be oversampling R +13? Why are they still oversampling D??
That is not correct.
Enthusiasm is a very imprecise measure of turnout. Many who are not enthusiastic will still turn out to vote for the Kenyan.
I expect the RATs will have a slight turnout advantage in November, which will make the results very close. If they do not, and the GOP runs even or better, it will be a Republican blowout.
Dim voters don't have to be enthusiastic, they simply show up for their share of the "street money". I have to say, however, that this much of a gap is not going to be overcome by normal levels of Dim cheating.