You keep using the verb “stay.” They are being deported, and thus will have to “return” through a legal process.
Being deported, currently the US government has stayed deportations so they are staying. No amount of claiming that the legal processes is working. Look at Judge Sullivan regarding Jeh Johnson and the Obama administration does not want the Judge to hold him in contempt of court because of the stay process for deportations of illegal immigrants. Sop how is Donald going to change this - mass deportations, close the border or mass tent cities to hold the illegals in to determine legality. Come now do not be deceived there will be no mass deportation or mass encampements of illegals. This would portray America like Palestine, Turkey or other countries that have massive amounts of people living in squalor whom are fleeing the poor conditions of their countries for freedom.