Everybody's favorite right-wing pressure group is getting involved in a key Senate race, in which the Democrats stand a very good chance of picking up an open Republican seat.

The Club For Growth is wading into the already nasty GOP Senate primary in New Mexico, launching a $200,000 ad buy against Rep. Heather Wilson for supporting the S-CHIP bill:

Considering the S-CHIP bill has been popular with the public at large, the GOP has a bit of a conundrum here: If they nominate Wilson's more conservative primary opponent, Rep. Steve Pearce, they could have a weaker candidate against Democratic Rep. Tom Udall. On the other hand, Wilson first has to make it past the party's activist base that votes more heavily in the primaries.