A detailed analysis of Romney’s various paths to the 270 electoral votes he would need to claim the presidency suggests he has a ceiling of somewhere right around 290 electoral votes.

While Romney’s team would absolutely take a 290-electoral-vote victory, that means he has only 20 electoral votes to play with — a paper-thin margin for error.

Romney’s relatively low electoral-vote ceiling isn’t unique to him. No Republican presidential nominee has received more than 300 electoral votes in more than two decades. (Vice President George H.W. Bush won 426 electoral votes in his 1988 victory over Massachusetts Gov. Michael Dukakis.)…

If Romney was able to duplicate Bush’s 2000 map, he would take 285 electoral votes — thanks to redistricting gains over the past decade.

But to do so, Romney would need not only to win the five swing states mentioned above — with the exception of Missouri, all of them are considered tossups (at worst) for the president at the moment — but also hang on to states such as North Carolina and Virginia where Bush cruised 12 years ago. (Obama carried both states in 2008.)