Nate Silver makes case that Romney may have already reached his peak

Did Romney peak this week? History says it is quite possible. While everyone eagerly scans polls to see what, if any, convention bounce the Obama reelection campaign gets this week from Charlotte (and it is way too early to tell), the New York Times' Nate Silver makes a pretty effective case that it may not necessarily matter:

There is a lot of focus on the bounce that a candidate gets after his convention ' that is, how the polls conducted just after the convention compare with the ones taken immediately beforehand.

But the more instructive comparison may be how the post-convention polls track with the actual election result ' it's Nov. 6 that we're really concerned about, after all.

On average, between 1968 and 2008, the challenging candidate led by 10 percentage points in polls conducted just after his convention. By comparison, the challenging candidate eventually lost the popular vote by an average of three points in these years. That means the post-convention polls overrated the challenger by an average of 13 points.

Though Silver, as one would hope and expect, proceeds to get all super-duper-mathy about it all, his thesis is rooted in basic common sense. To say that that a presidential challenger (or challenging party) should be at their electoral peak in the week after their convention is inherently logical. After all, they get a week on the stage (largely to themselves), and there is a bit of a rally effect within the party at convention time, barring a disaster at that convention.

An average of all the polls released on Tuesday and Wednesday of this week gave the president a very narrow edge of about one point. If it were true that challengers fade to the tune of double digits after the glow of their convention wears off, Mitt Romney could be in line for a defeat the likes of which we haven't seen in a generation.

But, before one starts booking January travel plans to Washington, D.C., there are a couple of caveats.

• This 13-point fade cited by Silver is, in no small part, reliant upon a fairly decent counter-bounce in the wake of the incumbent party's convention. President Obama, to be clear, is absolutely not guaranteed a bounce from this convention the likes of which we have seen in past years. There has been several data points during this cycle to suggest that the critical mass of persuadable voters in 2012 is nowhere near what it has been in past cycles.
• The incumbent party fades after their convention, as well, meaning we might have a bit of contradictory data. The same study Silver conducted showed that the incumbent has a fade of their own, albeit a dramatically smaller one. The incumbent party led by an average of 5 points after their convention. The final result, as noted earlier, was about three points. One could interpret that to mean that if the president is up by three or more points after this week, history would predict an Obama reelection. But the data has been variable. Some incumbent parties have sprinted to the finish line and actually built on their post-convention bounce (GHW Bush, 1988). While others have faded rather notably (John McCain, 2008).
• As Silver correctly notes, this fade has eroded over time, with only one dramatic fade for the out-party in the last four election cycles (George W. Bush, 2000). This is probably because party conventions are not providing the huge bump in support that they once did, as Mitt Romney found out so unceremoniously last week.

Caveats aside, there is a bit of history that Mitt Romney must concern himself with. Only three times in the modern era (1972, 1984, 1996) has a challenger not held the lead in the wake of their convention. Those challenging candidates went on to lose, and not by an insignificant margin.

Every cycle is different, of course, and I can't remember one where the race has been as relatively static as this one has been. But it would not be inaccurate, nor would it be unduly harsh, to suggest that, at this point, Mitt Romney is swimming against history.