The only reason I think of why John F*ckin' is ahead is cause he's marketing himself as a realist Republican in foreign policy to the American people. Its a testament to how much the debate in this country has shifted rightwards that he's taking a position in national security credited with the realist school in the Republican Party. President Bush as you know sounds like a Wilsonian Democrat on the need to spread American values to protect America's long term interests abroad. Whether that's going to continue to be the case into the fall remains to be seen.
Bush needs to start selling himself as positive, because Kerry has an automatic 45+% to work with, no matter what.
And lately Bush has been working hard to keep some conservatives from voting from him. It won't take many staying home to make Kerry the next prez.