what about doing a thing where you announce the imminent rounding up of all illegal aliens. but before that happens, if you are illegal & go back to your country on your own, you will be allowed to get in line for legal immigration. but you wait in your home country.  now, if you do get picked up by ice & they are the ones to send you to your country, you are put on a list where you can never be allowed back in this country. ever again. it would hopefully get most of them to leave on their own
United States