You folks are sadly confused. Both the Republicans and the Democrats, with the exception of a few politicians in the border states, are in favor of illegal immigration from Mexico and Central America. Cheap labor lets some businesses remain profitable, keeps the minimum wage down, and reduces the effect of the demographic bulge of the baby boom generation on the economy.
There are not enough politicians running in 2012 who would support a REAL controlled border and/or REAL crackdown on employers of illegals for such measures to ever be passed and enforced. Not to mention the fact that the next President to pass another amnesty bill will immediately get a couple of million new legal supporters.
If you build the wall, people will complain about the cost, the environment and the racism; if you crack down on employers, people will complain about the cost, the harassment of legitimate businesses and the racism. I'm all in favor of having a vision, but this one has blinkers on that fails to allow for a nasty little thing called reality.