How do they get back into the USA without a U.S. passport or visa?
Obama gave them papers, illegally. He does not have that authority but the Republicans refused to do anything to stop him.
From the article:
Under a little-known provision of the law, these “DACAmented” individuals – as they call themselves – can get the U.S. government’s permission to travel abroad and return.A huge added bonus: The legal re-entry into the U.S. can boost the chance to win permanent legal status.
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The so-called advance parole provision, which allows the DACA recipients to travel outside the U.S., is typically granted for educational, employment or humanitarian purposes.
Those granted advance parole can re-enter the country legally, which paves the way for possible permanent legal status to those who are later sponsored by a U.S. citizen, an employer or who marry a U.S. citizen.