Party ID Shifts

One of the biggest debates among polling junkies in this election cyle is over the issue of party ID weighting. Recent polls show many more Republican identifiers than in the past. To some, this represents a real shift in partisanship, but to others, it's largely an artifact of sampling problems and, therefore, polls should be weighted to control for it. I don't know the answer to this question, but it seems that if this does represent a real shift in partisanship, we should be picking up hints of it in the party registration data. Of course, people can shift their party ID without changing their party registration, but if there is a real sea change going on, you would expect at least some evidence of a Republican tide among new registrants (to mix some watery metaphors). As this article shows, that clearly not the case in NH. And from what I've seen in other states, Democrats seem to be doing as well or better than Republicans when it comes to new registrants.