This is from 2005, Romney did not stand a chance for reelection and four months later (after polls like these) he announced that he would not seek it.
Romney predicts ‘landslide’ reelection
Forecast with a catch: That’s if he runs again
By Michael Levenson, Globe Correspondent | August 27, 2005
Despite polls showing him trailing potential Democratic rivals, Governor Mitt Romney is confidently predicting that he would trounce the competition if he decides to run for reelection next year.
‘’Well, I win by a landslide in Massachusetts if I run for reelection. And that’s very possibly what I’m going to do,” Romney said in an interview with Chris Matthews that was televised nationally yesterday on the MSNBC political talk show ‘’Hardball.”
“The Globe survey of 503 adults, published Sunday, found that Reilly was backed by 51 percent of respondents, compared to 38 percent for Romney. In March, a Globe poll showed Reilly with 48 percent and Romney with 41 percent.
The poll also found that, when respondents were asked if Romney should be reelected, 30 percent said he should be reelected, and 51 percent said someone else should be elected.”
I come up with Romney at 46% approval in March 2006, not at all terrible for a Republican in an overwhelmingly Democratic state.
Voter opinion of Romney appears to have dropped since he announced he would not seek reelection, a step widely seen as preparation for a 2008 presidential campaign. His job approval rating was 46 percent, down from 51 percent in the August survey, while 47 percent disapprove of his performance, up from 42 percent. Still, Romney's personal popularity remains constant: 49 percent gave him a favorable rating, compared with 50 percent in August, and his unfavorable rating remaining at the 41 percent he received in the last survey. Source
It was after Mitt started campaigning for the Presidency that his approval rating dipped down into the thirties.
Depending on who you talk to Deval Patrick's approval rating is already in the thirties or lower. In a two way race only 32% of the voters would pick Patrick, and that would be lower if his Lieutenant Governor runs against him as an independent, at least according to one August 2009 report I've seen.
I don't see Romney as anything more than a half-full glass. If you want to call him half-empty, fine, but there are a lot worse politicians out there.