Well the difference in this case is that border crossing is a victimless crime, like drug use, and those other two aren't.

So technically as an anarchist I don't think that States can ever be contained at the "night-watchman" level that traditional minarchism prescribes...

But I think there's a funny thing about victimless crime enforcement... Both in the case of the drug war and immigration you start to have to erode fundamental aspects of 2nd, 4th amendment etc protections in order to do any "practical" level of law enforcement.