Even if Bush did win the popular vote... More voters may have turned out knowing that it was a popular vote in which the decision for President would have been made. Example, I'm in Oklahoma, I knew we'd vote Republican, hence I didn't waste my time at the voting booth as I'm a rep also... If it was a popular vote, I would have been in that booth casting my vote. You can say this for both reps and dems. So the "This guy would have won had it been a popular vote" argument is not a valid nor legitimate one.
Jamie