I think you're correct. Of course we won't catch and deport ALL of the illegals, but we can deport enough of them that would-be immigrants will see that it's a lot harder to get her and stay here than in the past. We can crack down on ENOUGH employers of illegals to make it less worth their while to hire them. We CAN build a wall from the Pacific to the Gulf of Mexico.
It's my perception that people who say we can't do any of this are those who have different goals than we do.
And for anyone who says that it's "impossible" or "impractical" I would suggest that they look to Australia, which accomplished the same thing that we want our government to do-and that it is Constitutionally obligated to do-and is better for it.
You can pass a law that qualifies every illegal for the death penalty, but unless that law can be realistically enforced it is less than worthless.
In addition, the logistics of enforcing some laws can be so difficult, it is almost no use having the law on the books. It feels good and nothing more.
If there are the 12 million illegals that are suggested, how many law enforcement personnel are going to be needed to process these people? Where will you hold them on a temporary basis? If they have been here for many years, where will you deport them to? How would you deal with the media reaction of showing scores of people herded into detention camps? Would you put them in buses to Mexico or rail cars? The logistics of the deportation option are completely infeasible.