Why, despite perennial griping, doesn't immigration matter more in the U.S.?

VDARE asks the question.

And, because of the magnitude of their defeats, we now have to endure the slings and arrows of the MainStream Media and its non-stop pontificating about how immigration reform doesn’t resonate at the polls.

See, for one example, Collins’ editorial cited above with its reference to the “fringe”.

Or read former Mexican foreign minister Jorge Castañeda’s gloating conversation with a Miami Herald reporter wherein he called Hunter and Tancredo “two crazies…who went nowhere…” in the presidential primaries. [A Mexican view of U.S. immigration debate, By Casey Woods, Miami Herald, February 17, 2008]