I don't think five million went home since 2000. I think were talking about five million more since then. That's 15 million at a minimum.
I think you hit the nail right on the head!
Time magazine quote:
The number of illegal aliens flooding into the US this year will total 3 million - enough to fill 22,000 Boeing 727-700 airliners, or 60 flights every day for a year.