As you know, Romney aides have taken to telling reporters that they think the 2012 election will unfold just as the 1980 election did. With Obama maintaining a small but persistent lead in the polls — and a slightly larger lead in swing states — they say they expect the race to break in Romney’s direction in the home stretch.

I laid out a few reasons last week why the historical comparison is imperfect. And in response to my post, Reagan biographer Craig Shirley, who wrote a book on the 1980 campaign, sends over some more interesting thoughts:

Beyond the fact that Romney is not even a poor imitation of Reagan; or that Obama is a vastly superior politician to Carter; or the fact that the economy is nowhere near as bad as it was in 1980; or that the world situation is far better than in 1980; what is most overlooked is that nearly every state was in play in 1980, unlike today.

Both candidates campaigned across the country; Reagan in New York City, Carter in Reagan’s California.

Some states like Wyoming were going to go Republican and Georgia was going to go Democratic, but hard as it is to believe only 32 years later, the South was considered a Democratic stronghold, New Jerry was considered a reliable Republican state in presidential years and both sides competed aggressively for Illinois, Texas, Michigan and other big prizes.

In the end, as we now know, Reagan took 44 states but many like Tennessee and Massachusetts he only won by the narrowest of margins.

This time around, the focus is on maybe nine swing states, and as noted before, the role of swing Democrats — Reagan Democrats, as they were called at the time — may be less important in this election. Meanwhile, Nate Cohn says he still thinks Romney has a credible path to victory, because of the economy and the resources the Romney camp is amassing, but he suggests that if a late break is what Romney and his advisers banking on, then history is not on their side:

Contrary to conventional wisdom, history suggests that undecided voters are unlikely to uniformly flock toward the challenger: Candidates almost always finish above their share of the vote in summer polling. While there are examples of challengers sweeping undecided voters, as Reagan did in 1980, the “1980 or bust” position is hardly enviable. The economy is bad enough that the 1980 scenario can’t be discounted, but the differences between 1980 and 2012 are too great to count on it—especially given Romney’s astonishingly bad numbers among undecided voters...

The question, however, isn’t if Romney could rebuild his brand, but how—and that’s where Romney’s real conundrum resides. Romney’s deficient conservative credentials limit his ability to tack to the center, a move which would have served him extremely well. Boston’s inability to effectively rebrand their candidate — despite sustained unpopularity since he ascended to national prominence — raises the question of whether they’re capable of improving his image at this late stage. If they couldn’t make Romney popular before, how will they do it now?

And this goes back to the fact that Romney ... isn’t Reagan; and that Obama ... isn’t Carter. I fully expect the race to tighten, and I’d say it’s still a toss-up, given the bad economy. But it’s interesting to ask why the Romney camp is spnning this scenario. I don’t know how heavily Romney and his advisers are banking on things unfolding this way, but the fact that they are telling folks this suggests they think they need a theory of the race that explains why they aren’t yet winning.