Your argument seems to be morphing into the "everybody else did it" fallacy that Dims usually turn to when they can't defend their position.
I think if you look at my posts to this board you will find that I have consistently complained that anti illegal immigration advocates have been unreasonable in their demands. I still believe that is true and that such advocates have circumvented a political process wherein they actually field such candidates rather than hijacking candidates without that position.
When Pat Buchannan wins the nomination or Tom Tancredo, I will happily agree with you. Until such time, the anti-illegal immigration crowd was an important factor on why Republicans lost in my opinion.