Any poll that puts an individual candidate (Bush) against a generic candidate (democrat)presents a biased and flawed result. It has been proven over and over again. Just look at the results when it is Bush vs a specific democrat, whether it is Hillary, Gore or any other democrat candidate, Bush holds a 10+ point lead over any specific democrat candidate.
Opinion Dynamics did a poll Aug. 12 - 13 pitting Bush/Cheney vs Gore/Hillary - the result was Bush/Cheney - 50%, Gore/Hillary - 39%.
http://www.pollingreport.com/wh04gen.htm