The LAN line telephone argument is weak at best, this isn't Dewey beats Truman. The GWU Battleground poll is a bi-partisan poll conducted independently by 2 separate companies: Tarrance Group and Lake Research Partners.

However when I saw the data itself, it asks for very decisive answers and they do not read out the "undecided" bit. I think there would've been a higher percentage of undecided voters.

Other than that, it seems to reflect the current climate, it's an undecided race and anyones presidency to take.