There are different opinions regarding the legality of the Deferred Action for Childhood Arrivals (DACA) which was established by the Obama administration in 2012. Some people claim it is constitutional or legal while others – just like the ten attorneys general who allegedly pressured President Trump to rescind the program – believe otherwise.
Although President Trump announced that he was rescinding the program through the Memorandum on Rescission of Deferred Action for Childhood Arrivals on September 05, 2017, it is worthy to note that the Supreme Court has not yet ruled on the constitutionality of the program thus, calling it legal or illegal is still presumptive. Hence, there is not exact answer to this question, yet. It may or may not be considered as legal or constitutional, but only time can tell.