Sometimes I think that we make mistakes when we tempt reasonable people to break the law. Prohibition would be an example. When I was in a high school debate on legalizing pot, I came up with an argument that said that since marijuana is a gateway drug to other drugs, we can take its "gateway" status away by making it legal. (I am not now prepared to endorse this argument now, however).
People like to talk about what to do about illegal immigrants (Path to citizenship? Attrition through enforcement?), and we also like to talk about border security (if we give a path to citizenship, and people are still entering illegally, aren't we going to repeat the cycle?), but could we reduce the problem of illegal immigration by making legal immigration easier?
What people sometimes say is we are a nation of immigrants, and that while we oppose illegal immigration, legal immigration is just fine. If that is our position, then we ought to make it easier to immigrate by increasing quotas. If, on the other hand, the real problem isn't just illegal immigration, but immigration itself, then we should be willing to say that honestly.