The most unpopular nominee ever?

So to get a better sense of how strong (or weak) Romney will be, forget about the head-to-head numbers for a few months; right now, they say more about Obama’s vulnerability than Mitt’s might. The more suggestive metric—the one that actually has some history of predicting a challenger’s general-election prowess—is his favorable rating.

Unfortunately, this is terrible news for Mitt, because he currently boasts the worst primary-season favorable-unfavorable split of any major-party nominee of the last 36 years (at least). There have been roughly 20 polls released in the last two months; only one gives him a positive favorable rating. The rest of the surveys show Romney’s unfavorables outstripping his favorables, often by as many as 20 percentage points. On five occasions, his unfavorable rating has topped 50 percent; his favorable rating has fallen into the 20s five times as well. As of March 12, when the last of these polls was released, Romney was averaging 49.6 percent unfavorable to 37.6 percent favorable—a gap of 11.7 points.

The depth and duration of Romney’s favorability dip is unprecedented, even during a heated primary battle. More often than not, the eventual winner enjoys positive favorable ratings the March-April before the election. Carter was at 74 percent favorable on March 27, 1976; Reagan was at 41 percent favorable to 34 percent unfavorable on April 18, 1980; George W. Bush was at 63 percent favorable to 32 percent unfavorable on March 10, 2000 (a split that was unchanged a month-and-a-half later); and over the month of March 2008, Obama’s favorable rating outstripped his unfavorable rating by an average of 19 percentage points.