The solution to the problem is to punish employers that hire illegals, but you can not punish them if you do not give them the means to determine who is legal and who is not. Slove that problem and enforce the law and you have solved the illegal immigration problem. No need to have troops on the border, leave it mostly open. Go after employers and the illegals will go home on their own.
I can't agree with either of those propositions. Even if we have a liberal immigration policy, there are still certain people we can't be letting in under any circumstances. And attempting to enforce immigration law in the interior of the country, rather than at the border, will create headaches for citizens as well, and could accelerate the drive for a national ID.