Technically he could.
But if you have been paying attention you might recall that Obama implemented the Dream Act with an EO.
Trump wrote an EO reversing that policy and the courts put a hold on that order and then said that ending it was unconstitutional.
The Dream act EO is just a few years old just imagine trying to reverse an EO over 60 years old.
There was never an Executive Order regarding “The Dream Act”.
It was simply a policy memorandum from Secretary of Homeland Security Janet Napolitano.
https://en.wikipedia.org/wiki/Deferred_Action_for_Childhood_Arrivals#Implementation