Considering all of the disease there is, currently, with Republican leadership all around the country, these numbers are pretty damn good.
Not for an incumbent in a Republican state. McCaskill hasn't even started campaigning yet.
Which is precisely why I am not worried. None of these guys have started campaigning yet. Once they do, you will see a totally different dynamic to this race and all the other Senate races.
You also said you weren't worried about the Colorado Senate seat either and it was a case where Democrats "were making a big deal out of nothing"