For Trump to "do the same thing" doesn't disqualify it out of hand just because you don't like it, if the precedent now says that this is a legitimate use of executive power.
That's the thing, Fenring:
Republicans never acknowledged that it was a legitimate use of executive power.They have continually criticized Obama's actions as being illegitimate. They have taken it to court. They have characterized the Democratic party as ignoring the Constitution (as Seriati did). They have taken the position that
they are the defenders of the Constitution, and not those despicable Democrats. Can you point out any instance until now when Republicans admitted that Obama had that authority, or haven't fought against it?
But now, when their fearless leader announces he will do something similar, suddenly it has become a precedent. After having fought against and spat on it for so long, suddenly it is a "long accepted" right of the executive office when their guy does it, and no one can say otherwise.

This is what the Republican party has been doing, again and again and again, over the past couple of years. Pointing at actions they reamed Obama for as justification for what they want to do. As if the Democrat party, which they have vilified for years, is suddenly the standard of American principles. And not the core values of the Democrat party, like justice, fairness, belief in science and such, but
the parts that they vilified, rightly or wrongly.
Sorry, Fenring. It is complete "whataboutism," at the most basic, elementary-school level.
In fact, I would argue that it is worse. Because while Obama may have overreached his authority over Congress in not enforcing immigration laws for DACA immigrants, Trump is overreaching his authority over the Constitution itself, which is far worse by any standard.