Good point, from a reader:

First Read doesn’t mention that in January, Quinnipiac had Blumenthal leading McMahon by 41 points, and in March by 33 points. 

Now they have his lead at 25- still large, but the trend is not his friend, and McMahon hasn’t even started spending $50 million against him in the general election yet. This will likely become a tight race (it may be one already- Rasmussen’s last poll, taken immediately after the scandal broke, gave Blumenthal only a 3-point lead).