TL/DR: Obama, through cult of personality, has amassed unprecedented executive power, and now cedes that power to Trump
Bush the Lesser led the most imperial presidency since Nixon, at least up until his time. With no patience for due process, Bush set about changing the law through executive action. Bush showed very little knowledge of either law or political history, he may have been acting out of ignorance or bad advice.
In 2008 candidate Obama (rightfully) decried this as an unconstitutional power grab.
Evidently, sometime during the Obama regime the Constitution was changed, because it did not take long to change his tune. Obama is well aware that he is acting extra-Constitutionally, he is smart and he has studied the document.
The Constitution has not changed, still Obama has expanded executive overreach far beyond anything in history outside times of major war; certainly far beyond anything that Nixon could dream of.
Now Trump, the most unprepared person in modern history–whose behavior and character can best be described as erratic–is assuming presidential power.
I would love to see someone like candidate Obama become president some day.