Theoretically you can be immigration checked anywhere within 100 miles of any US border, which includes a huge majority of the populace. See https://www.aclu.or

Theoretically you can be immigration checked anywhere within 100 miles of any US border, which includes a huge majority of the populace. See https://www.aclu.org/other/constitution-100-mile-border-zone https://www.aclu.org/other/constitution-100-mile-border-zone