Goss subscribes to the 11.5 million total figure, so he believes the total number who will not apply for RPI status will be 3.5 million. If 900,000 become legal by other means, and then, say — and this is just a guess — another 600,000 leave the United States, that still leaves two million illegal immigrants in the country who will not become part of the new system.

What happens to them? They are the missing millions of immigration reform.

“There would seem to be three options,” writes Mark Krikorian of the Center for Immigration Studies, which strongly opposes the Gang of Eight bill. “They’d all be deported; they’d leave of their own accord — self-deportation — because of E-Verify (though it wouldn’t be retroactive under the Gang bill, so it would apply to them only if they were to change jobs); or they’d just wait around for the next amnesty, which is the guaranteed outcome.”

Krikorian believes there is zero likelihood that two million people will be deported. That seems a reasonable assumption. And it’s true that implementing the E-Verify system, even if it overcomes business opposition, lack of administration support, and perhaps court challenges, will take years. So it seems likely that a large number of currently illegal immigrants will just stay in the United States — still “in the shadows.”