It's not just several groups and to a greater or lesser extent. It's pretty much across the board, including people who would be expected to vote for him. That must make the below-40 number Gallup has handed out even more painful for the White House.
Nate Silver looks at the numbers:
So far for the third quarter (which began July 1), his Gallup approval rating has averaged 43.3 percent as compared with 46.8 percent in the second quarter, a decline of 3.5 points. There have been 76 occasions in the past when a president’s approval ratings have dropped by more than that from quarter to quarter. If Mr. Obama’s approval ratings remain near the 40 percent mark or below for the rest of August and September, he has a chance to move up the list of historically significant declines. But so far this is within normal bounds.
If the decline in Mr. Obama’s approval ratings is not especially deep, however, it is broad — affecting essentially all demographic groups, including many that will be critical to his re-election efforts.
Want to feel worse? Lack of confidence feeds on itself. Take a look at this injustice!
...It may be that a lack of confidence in Mr. Obama — as well as the Republicans in Congress — will itself prove to be an impediment to recovery, and that these numbers could continue to erode. One does get the sense that we’re nearing an inflection point.