I have said this before, but it bears repeating.
Any meaningful immigration reform that is not essentially an amnesty will result in a lot of people who want to come here not being able to come here. People who try to deny this fact by claiming that the immigrants who are here illegally "should have come here legally" or that "they are against illegal immigrants, not immigrants," as if the only issue were paperwork, are not doing anyone any favors. (Some are presumably lying, although some may actually believe what they say).
The fact of the matter is, the issue isn't immigrants who come here illegally vs. those who come here legally. The issue is immigrants who are a net benefit from thsoe who are a net detriment. Or, put another way, those immigrants we want vs. those we don't.
What I would say is that "I am not anti-immigrant, I am against those immigrants who do not in my opinion improve our society." I am, of course, against ilegal immigration, but part of the reason is that it confounds our ability to keep out those whom we wish to keep out.
It is wrong to pretend that those who are here illegally will be welcome under the new system as long as they go back to their country and then decide to come here legally. Many of them will simply never get back into the U.S. This claim gives people false hope and will eventually earn their wrath at our duplicity. Moreover, it allows people to avoid dealing with the fact that a restricitonist position will cause some suffering.
Yes, I admit that immigration restriction will keep some people out of my country, and will thereby cause suffering amongst some who wish to come here, suffering that could be alleviated by just letting them in. I think that that is an acceptable price to pay. You can call me heartless, or cruel. But I am honest about what restriction will entail.
In the end no good will come from fantasizing that we can restrict immigration levels without someone getting hurt in the process. We need to have truth on our side if we are to prevail.
That is all.