I encourage any liberal who supports comprehensive immigration reform to go read "Why Liberals Should Oppose the Immigration Bill/It's about low-wage American workers" by T. A. Frank at The New Republic. Check it out here.

After reading it, come back here and leave a comment with your thoughts or concerns. TNR only lets subscribers leave comments, but anyone can leave comments here.

While Frank supports some form of legalization and this site supports attrition, and he gives too much credence to studies rather than what people do [1], he does make arguments that will hopefully be persuasive to many. For instance:

...All in all, I became convinced that high levels of low-skill immigration are good for wealthy Americans and bad for poor Americans. Far more important, high levels of illegal immigration—when you start to get into the millions, as we have—undermines unions and labor standards, lowers wages, heightens social tensions, strains state budgets, widens income inequality, subverts the rule of law, and exacerbates class divides. The effects go far beyond wages, because few undocumented workers earn enough to cover anything close to the cost of government services (such as education for their children) they require, and those services are most important to low-income Americans. In short, it’s an immense blow to America’s working class and poor...

...If I have a plea to my fellow liberals more broadly, it’s that they focus more of their empathy on fellow Americans being left behind. Because we increasingly live in bubbles, many of us are at best only abstractly aware of how cruelly circumstances of unskilled Americans have deteriorated over the past few decades. Even as these Americans have lost their well-paid manufacturing jobs, Washington has looked the other way while millions of low-skilled unauthorized immigrants have competed with them for low-skilled service jobs. The insouciance of privileged Americans toward the effects of this on life among less-privileged Americans is, in my view, a betrayal of citizenship...