[Melas]

It’s like being high. Possession of marijuana is illegal. However, if the police find you high in your living room, and you’ve smoked all of your marijuana leaving them nothing to find, there isn’t a damned thing they can do. Being high isn’t illegal in your living room, but possessing marijuana is, and you don’t have any (left).

[Political Junkie Too]

That must be what the 9th Circuit is doing, because the illegal act isn't just the illegal crossing itself, it's also the continued illegal presence without authorization.

If it isn't illegal to be present illegally, then why is it illegal to hide someone who is here illegally, or to transport someone who is here illegally?

-PJ