The immigration debate in the US is so biased that there is little chance that any intelligent discussion can take place.
To some neo-conservatives immigration is the mother of all evils and blamed for everything that is wrong except, at least for the time being, the war in Iraq. On the other side of the spectrum we have those who believe that immigration is good for the US and that since we are a nation of immigrants everyone should be welcomed.
Behind the slogans, self serving names, the posturing and of course the profiteering by some dubious and certainly biased media personalities, the truth is that everyone in both sides of the argument are simply human beings; human beings that react as such when confronted with real and/or perceived threats.
In the end, everyone in this epic confrontation shares the same primal calling and motivation; survival!
In the US, the anti-immigration zealots are not really concerned with jobs, welfare and the economy. Why should they? If there is something that the US has proven through out its history is that we are the best there is when it comes to assimilating and adapting. We are extremely good at thriving in adverse conditions and certainly a couple million immigrants are not going to change that.
Further, immigrants are both producers and consumers and that is what our economic system is based on. We might need to tweak a little thing here and there to help immigrants adapt and produce more than they consume, but that is not a problem for a strong and creative economy such as the US economy.
The real concern that conservative zealots and other xenophobic fanatics have is that they perceive Hispanic immigration as a threat to the survival of their particular brand of American culture. Further, most of them are really advocates of a policy of ethnic cleansing disguised as an immigration policy.