In the latest one, the % of people saying the economy was "fairly good" fell from 22% to 21%. Hardly a major drop. And in fact the % of people saying the economy was performing fairly bad dropped from 46% to 45%, so it's not clear that there's been any deterioration at all. And on the one from this morning, people's outlook on the economy actually rose from the previous polling. So on both polls you see Obama taking hits on his performance in managing the economy, but not a major drop in how people view the economy itself.
This really doesn't make sense, considering that the economy is by far the most important issue for voters. Another thing that's strange: NYT poll has 6 percent of those disapproving of the president's job performance planning to vote for him anyway.