[T]he numbers are noteworthy, because even before this week, Carter has generally been assumed by some Dems to be terrifyingly controversial, largely because of his writings on the Middle East.
With the focus on the Mideast heating up again, Carter will likely be making more news, and the Obama administration will likely be distancing itself from him again, as it did yesterday. Worth recalling that the public doesn’t take all that dim a view of the stuff he’s done since leaving the White House.
I don' t think that's a reasonable interpretation of the poll, however. Carter is one of four modern presidents who have benefited from a strong post-presidential reputation campaign. Well, one of the four, Nixon, didn't benefit very much from what was, in his case, largely a one-man operation. The two big success stories were the two organized by others on behalf of Presidents Reagan and Kennedy. Both presidents, as a result, are pretty significantly overrated in polls about past presidents (here's a good sampling).
The fourth story is Carter's. Carter, like Nixon, has pretty much run a one-man operation to improve his reputation. But Carter's "new" reputation is almost entirely separated from his presidency, and I think, almost entirely separated from issues of public policy. When people say they approve of Carter's post-presidency, I think it's almost certainly the case that they are thinking about building houses, serving as an election observer, and perhaps writing books of poetry and religious belief. I very much doubt that the first thing that comes to mind for very many people is Carter's views on Palestinians. They see good works, not good policy -- in fact, people still (correctly; I guess I should add a IMO) think he was a dud as a president.
Bottom line? I think Democrats would be well-advised to continue to keep as much distance from Carter as possible.
[Update]: Matt Yglesias makes a good point about this, too, plus he has a way better post title than I do.