I don't know if "illegal immigrant" is well-defined enough to come up with a clear rule. Someone who is not eligible to request asylum could definitively be ca

I don't know if "illegal immigrant" is well-defined enough to come up with a clear rule. Someone who is not eligible to request asylum could definitively be called an illegal immigrant. Treaties signed and ratified by the US (which have the force of law in the US) require that refugees not be punished for unauthorized entry or presence if they present themselves to the authorities and request asylum, so they would definitively not be illegal immigrants. Someone who is eligible to request asylum but hasn't yet done so would be in a bit of a grey area. You probably haven't heard of this before because asylum seekers are a fairly small portion of immigrants. The number of asylum seekers per year only crossed 100k/year in the past year or so and prior to about 2015 was less than half of that. The total number of illegal immigrants has been close to 1 million/year at some points. This has only made it into the media because of the recent policy change to take punitive actions towards asylum seekers in direct violation of the US's treaty obligations.