Silver is right that the current GOP field lacks a widely praised figure who is held in esteem by both Democrats and Republicans, which may be a reflection of the candidates who have chosen to run or the increasingly polarized nature of our country's politics. It's not clear, however, that the absence of such a figure will matter.
The reality is that the economy plays a dominant role in presidential outcomes. To be sure, public reputations may matter in relatively extreme cases. In the past, for instance, I've argued that Hillary Clinton and Sarah Palin might underperform in the general election due to their polarizing public profiles (you could make the same argument for Newt Gingrich or other especially unpopular candidates). Other than Palin, however, it's not clear that the composition of the Republican field will matter much for the GOP's chances in 2012. The numbers that ultimately matter are economic growth, not early-stage polling.