I don't know that I would describe a low-end/high-end scenario as yielding an accurate result in this instance.

The Time and Newsweek numbers are historically abberant.

Both generics have the Dems getting over 50% of the vote, with margins over 15%.

CNN has it 58% - 38%.

Using presidential elections as proxies, only 3 of the last 37 presidential elections had the Dems getting more than 50% of the vote with margins of victory over 10%.

I'm reluctant to ignore that historical perspective, and think that merely averaging the highs and the lows is not going to get you to an accurate average.

I may be completely wrong, but these polls don't seem to fit with historical patterns, and I don't see evidence that an alteration of those patterns is warranted.