Favorability ratings show the former Massachusetts governor has suffered real damage over the last week.

Now that everyone has decided Mitt Romney is the inevitable nominee again, they're ready for a deep dive into the nitty-gritty policy differences between Romney and President Obama. Nah, just kidding -- it's time for Romney-Obama horserace coverage, rather than Romney-Gingrich horserace coverage. Specifically, many commentators are discussing whether the tough primary season will serve to toughen Romney up for the general election, as the bruising 2008 primary did for Barack Obama, or damage him irreparably, like Barry Goldwater in 1964 or Gerald Ford in 1976. Ron Fournier noted last night that long contests tend to be bad for GOP candidates. Some smart writers from liberal and conservative outlets have weighed in, too, including Robert Costa and Jonathan Chait.

Speculation aside, one quantitative way to measure the damage is in favorability ratings. This vertigo-inducing graph is from Talking Points Memo's PollTracker, which aggregates results from many polls. Unlike Newt Gingrich, who enthuses the GOP base but has had an overwhelmingly negative image among the general electorate for the entire race, Romney has had trouble energizing rank-and-file conservatives but has remained generally likable.

Over the last week or so, however, that's been seriously eroded. Romney's unfavorable rating is veering toward 50 percent, an all-time high, while his favorability rating has nose-dived to an all-time low of 29 percent. While candidates' support can fluctuate in primaries -- something we've seen time and again during the GOP race -- it's harder to recover lost favorability. That's scary stuff for Boston as they look toward the general election. By way of comparison, Barack Obama had a 61 percent favorable rating in Gallup's poll at the same time in the 2008 race.