Again, we're talking about polls, which is nothing more than a popularity contest. Most of the tough/right decisions tend to be the most unpopular ones. Not to imply that Bush makes all the right decisions, but you get the point.
Presidents who make tough decisions will always go through periods of unpopularity.
When Clinton was trying to actually do things in his first two years, he was pretty unpopular. When he did nothing in his last 6 years, he was very popular.
The public is like children. Children love parents who let them eat sweets before dinner, don't give them a set bedtime, and don't make them go to school. Then, when they grow up unprepared to function in the world, they blame their parents for all the things they loved as children.
Presidents who put their own popularity first do not prepare the public to deal with unpleasant issues, and pass looming problems that maybe could have been contained on to their successors. That is exactly what Clinton did, and what Bush is attempting to avoid doing. I don't claim that everything he's done is right, but he has already taken on far more contentious issues in 4 years than Clinton did in 8 years.
As far as Bush's popularity among blacks is concerned, who cares? The vast majority of blacks wouldn't like him no matter what he did, so there isn't much point in wasting a lot of time fretting over their opinions.
