Nate Cohn pointed out that it looks like this pollster is weighting it's results to conform to 2012's 51-47 Presidential outcome, which partly explains the big Republican slant since some people in most polls tend to say they voted for the winner when they did not.
This pollster is using the same modeling that RAND used in 2012 when they nailed the election with pretty good accuracy. This is a test to see if it they were just lucky or good. One would assume the same "voted for the winner" in 2008 bias for the 2012 cycle.
Obviously, the jury is still out on this type of polling, generally.
Once again, this is not a poll. It is a pre-selected panel, which as Nate Cohn pointed out, is weighted to conform to 51-47 2012 results. This thread and panel poll is meaningless.