NumbersUSA is one of those anti-human groups who only oppose immigration (NOT illegal immigration -- all immigration) because it's part of their radical liberal zero population growth philosophy.
One of the leaders of this anti-human movement is John Tanton, a Planned Parenthood and anti-immigration leader who is a contributor to the Tom Tancredo campaign.
Tancredo took a lot of flack for accepting Tanton's support, but he apparently sees nothing wrong with it. It's very disappointing when conservatives don't see what kind of scum these people are who are trying to jump into bed with them to further their radical agenda.
Personally, I don’t see anything wrong with a zero population growth philosophy. The real issue is how you implement it. Depriving liberty should never be an option. On the other hand, taking away freebies, supplements and incentives sounds good to me. Regulating immigration so that it acts as a positive force for our nation was the norm until the 60’s. Then it was morphed into a policy of ‘anything goes’ regardless of it’s effect on the nation.