A Partisan Advantage for Obama?

As I pointed out at the end of August, I see political and economic context of the election as favoring Mitt Romney, though not overwhelmingly so.  In fact, I think that Romney's gains after the first debate partly reflected a dissatisfied electorate responding to a campaign event that pushed them in the "right" direction.   But one thing I find interesting is that despite a reversal of fortunes in the last few weeks, there seems to be a clear floor below which Obama's support will not fall, and Mitt Romney has not been able to do any better than draw even or periodically take a very narrow lead.

One thing that may be benefiting Obama could have little to do with the standard indicators of national conditions and may have even less to do with either of the candidates or their campaigns. Simply put, I think a case can be made that the Republican brand name is acting as a drag on Mitt Romney's candidacy.  This idea has gotten a little bit of attention from some journalists, and the data I present below largely provide additional support.

One way of assessing the relative value of party for each of the candidates is by looking at rates of party affiliation in the electorate.  The figure posted below was generated using the pollster.com dashboard and includes the results of hundreds of polls.   These data show that the Democrats have held an affiliation advantage throughout the 2012 campaign, one that has ebbed and flowed a little bit and now stands at approximately six percentage points.  Of course it is possible that slight differences in loyalty (Republicans have been more loyal than Democrats in SOME elections) and turnout might mitigate the the Democratic advantage in affiliation.  Still, I can't imagine this difference has no effect on the current contest.

But party identification isn't the whole story.  Instead, there appears to be a broader problem having to do with the general image of the Republican Party, especially when compared to the image of the Democratic Party.

The figure posted below summarizes the "favorability" of both parties, using results from several polls that have asked respondents to rate their feelings toward the parties as either favorable or unfavorable.  I don't have nearly the same number of data points here as for the figure on party identification, but the pattern is very clear: throughout this campaign period the Democratic Party has been viewed more positively than the Republican Party.  In fact, there is not a single poll in this series in which the Republican party registered a net positive rating, and not a single case in which the net Republican rating was higher than the net Democrat rating.  The average net rating for the Republican Party in this series is -13, whereas the average for the Democratic Party is +.3.  To be sure, the net rating for the Democratic Party is sometimes in the negative, and the gap toward the end of the series is not as great as it was in the wake of the Democratic convention, but it is clear that the Democrats hold an advantage on this front.

Data taken from pollingreport.com and pollster.com.  The dots represent individual polls, and the lines are the smoothed lowess trends in the series.

Of course, there is little doubt that these two things--Democratic advantages in party ID and party image--are connected to each other.  Still the relative stability of the difference, and the approximately 10 point Democratic advantage in the most recent polls, must be working in Obama's favor.  Is this what's keeping a president with tepid approval numbers and a still-sluggish economy afloat?  If so, would there be any payoff for Obama to run not just against Mitt Romney but also against the Republican Party in the closing days of the campaign?

Just to be clear, I'm not arguing that the public is wild about the Democratic party; just that the Democratic Party is viewed much more positively (or less negatively, if you will) than the Republican Party.