"Chief Justice John G. Roberts Jr. prodded the Obama administration Monday to explain President Obama’s immigration flip-flop, when Mr. Obama in 2014 reversed himself and decided he did, after all, have powers to grant a tentative amnesty to as many as 5 million illegal immigrants.

Mr. Obama had repeatedly denied he had that kind of power, then after the 2014 election, when Congress refused to act on his policies, the president claimed a do-over and said he did have the power."
I would surmise Obama thought he was now the Ruler of the land with nothing to prevent him from making law with the stroke of a pen or a phone call. Reality might be setting in now, but not too sure about that.