http://www.breitbart.com/big-government/2014/06/16/mccarthy-labrador-about-equal-on-supporting-amnesty/
As your link says, he got a C+ at the time (since then he's felt the heat and voted right). No indictment of NumbersUSA there.
Ive listened to about 5 or 10 interviews with him all over the place. He is 90% Rubio in his talk.