As so often, Jon Rauch provides it:
Liberals are right to say that bringing unauthorized aliens into the open would make them less vulnerable to exploitation and easier for law enforcement to track, but conservatives are also right to say that mass normalization might stimulate more unauthorized immigration and erode respect for the law. Where illegal migration is concerned, the country will have to make a political choice. Mine, for what it’s worth, would be to legalize some but not all.
The Dish 