I've seen no candidate polling. Only that Jeff Bingaman has a 59% approval rating.
It's an uphill race, but not out of reach. Bingaman has won reelection more on the basis of his opponents' weaknesses rather than his own strengths. If McCulloch can get sufficient funding, this race has potential.
I read a couple of weeks ago that McCulloch actually outraised Pfeffer, 140k to 20k. I believe nearly all of his money came from Fundrasing and not himself. However, it should be mentioned that Bingaman has over a million ready to go.