The OP mentioned only the undocumented,
Someone sneaks over the border.....how are they documented?
How are the undocumented not here illegally?
You can't wrap your head around the big word?
Undocumented means there's no evidence they're not who and what they claim to be. If a fellow who doesn't speak English and is unfamiliar with our customs claims he was born in Los Angeles, we have no way of proving he wasn't because
he's undocumented.
Catch someone sneaking across the border and he's not undocumented, he's an illegal caught in the act. His arrest for being caught sneaking across the border documents his status as an illegal immigrant. But just suspect someone of sneaking across the border and you can call him any name in the book but you can't do a thing about it.
We don't have a mandatory national ID card in this country. It would solve so many problems if we did, from immigration to voting eligibility, but there are people in this country with political objections to having to acquire a national ID, establishing such a database with their personal info in it (like they aren't already in a database like that) so we're all stuck with dealing with major social problems for the lack of it.
The "illegal immigrant" tag cover two different groups of people in the country with distinct differences in status. One is the actual illegal, someone who we can document came into this country illegally by being caught at the border, or came here legally on a visa and didn't go home when they were supposed to. These people are arrested and deported as fast as we can process them.
The other group who certain people like to lump in with illegals is the many undocumented people we have in this country. We think they shouldn't be here but we can't prove it. There's no record of them arriving here, there's no record of them visiting and their visit exceeding its expiration date, there's no record of anything that would allow us to take action against them.
We can ask them to go back home, or get them into a situation where it might seem to them to be in their best interests to own up and volunteer to go back home, but we can't force them to do a thing because it's impossible to prove they weren't born in the US if they claim they were.
And that's because
they're undocumented.