While I sympathize with cracking down on deliberately exploitative employers - those who employ undocumented workers so that they can increase their profits by

• paying less than a fair market wage
• preclude union organization
• cheat workers of fairly earned wages
• abuse workers by violating OSHA protections

I am extremely resistant to the idea of empowering The Govermment with the right to determine with whom _I_ a born US Citizen, can and cannot contract with. I am even more leary of giving the same government that so blithely has tapped my phone and sent people to prison in Guantanamo on what amounts to Constitutionally prohibited Writs of Attainder, with the power to require that I carry proof of my citizenship and personhood on a regular basis.

And if you are going to enforce the kind of employer focussed punishments you speak of, you will need at the very least, both of those powers ceded to The Government. Note that today there is no provision in the US Constitution that cedes those powers to the US Government.

Is the supposed harm caused by undocumented workers so great that we are willing to surrender that much of our liberty to avoid that cost?

Are there really no other solutions? I would argue that there are, but that they require a fair amount of political courage because the underlying motivations driving this round of xenophobia (its a 40-50yr cycle that has historically occurred in the USA) are based in fear and racism, both powerful memes that run through this nation.