Walter Shapiro reports on the mood among Republicans in Ohio:

There are only two plausible explanations for what is going on this week in this swing state central to virtually all Mitt Romney’s victory strategies.

Either many top Ohio Republicans are in the grips of the worst panic attack since an Orson Welles 1938 radio drama convinced thousands that the earth was under attack by Martians. Or more likely, judging from the comments of these GOP insiders, Romney’s hopes of carrying Ohio are fast dwindling to something like the odds of winning the Powerball jackpot.

According to the RCP average for Ohio, Romney is polling at 43.9% to Obama’s 49.3%. By way of comparison, the final RCP average for Ohio just before the 2008 election was 2.5 points. Obama won the state by 4 points four years ago, and it appears that he could improve on that result this time. As we all know, no Republican has ever won a presidential election without carrying Ohio, and it would be difficult, though not impossible, for Romney to win without the state this year. As some of the Republicans in Shapiro’s article explain, Romney’s weakness in the state is that he has been defined in the most unflattering way in the minds of many Ohioans, and we can see that reflected in his unfavorability rating.

According to one swing state poll taken earlier this month, Purple Strategies, Romney’s fav/unfav in Ohio is 36-52%. The good news for Romney is that at least some of the people who don’t like him are still willing to vote for him. In that poll, Obama leads 48-44%. It is extremely difficult for a candidate to win a majority of the vote in a state when he is so widely disliked, and nothing has happened in the ten days since that poll was conducted that would make Romney’s favorability go up. This particular poll was conducted during the week that the fundraiser video came out, but likely does not reflect the full impact of Romney’s 47% comments. Looking at other polls taken around the same time in Ohio, Romney’s unfavorability is always higher than his favorability and normally reaches 50%. If anything, Romney’s favorability in the state is going to get worse in the coming weeks as the ads containing his 47% comments continue to air.

One reason that Romney’s unusually high unfavorability matters so much at this point is that it makes it very difficult for Romney to change the way that most voters perceive him. Once a negative first impression of a candidate has been made, whatever the candidate does to repair that damage tends to be dismissed or ignored as pandering or proof of the candidate’s desperation. Because so much of the pro-Romney argument is closely identified with him and his career, it is much harder for voters to distinguish between their unfavorable response to Romney as a person and their reaction to his campaign message. That doesn’t mean that Romney’s message would necessarily be all that appealing if he weren’t so unlikable, but because of his high unfavorable ratings many of the voters he would need to win over may simply stop listening to what he says.