I don’t know if you can put a few hundred thousand names on a single pardon or not.
I bring it up simply because it is another reason the concept is absurd. You can pardon someone for robbing a bank, but if they go out the very next day and rob a bank, they are not protected by that pardon. They’ll need another one.
i.e. even if Obama could pardon them all individually, the moment Trump becomes president the pardon is null and void IF they are still in the country illegally. It’s a fresh new crime, committed after the pardon was signed.
The whole thing is kinda like the “what of the electors for Trump vote for Hillary” meme. It’s ludicrous on the face of it.
Agree - that’s what I was saying initially. They would still have to leave before being caught, even if pardoned, to be clean.