Trump deported more people already living in the US; Clinton and Obama deported more at the border, by enough that total deportations were higher.

Actually, Clinton deported more in both ways. We weren't counting people deported at the border as deportees at the time.

Turning away somebody at a border is not deportation.

It's part of the deportation stats and the only things that makes the “Trump deported more than Obama” thing even technically true.

Obviously, yes, there is a substantive difference between removing someone who has only entered so far as the border checkpoint is on the US side of the border and removing someone who has been living in the US. That's the whole point of pointing it out.

Well, it's been counted that way since the 2nd bush administration