Then why does Rasmussen have him at 43/44% for the last week? I agree that Bush's numbers are nothing to write home about, but I don't believe the CBS poll, AP poll or this Gallup poll. Further, if someone did a poll of "likely to vote" respondents I'll wager Bush would be at 48/49%.
Many polls have Dubya in the mid 30s. Rasmussen in the low 40s. That's really the only one. The fact is that neither number is notably good and the idea that it's a somehow good thing that Bush isn't at a rating of 36, but in fact a rating of 43, is pretty silly to me. Both numbers stink (and show broad disapproval) and the truth is probably somewhere between 36 and 43.
I think Rasmussen does poll "likely voters" and I think his poll is the best because he polls daily and runs a three day average. The question never changes.