From Real Clear Politics:
The basic argument for why Romney is being written off far too early is pretty simple. He trails the incumbent president by 48.2 percent to 45.3 percent in the RCP Average seven weeks before the election. There are very few races that have been this close, this far out from Election Day, that would be characterized as anything other than a tossup.
I’m not as sanguine because the Electoral College map looks pretty bad for Romney, but this piece makes a lot of good points.