I'm starting to wonder if the good sportsmanship that's going around with Trump, Clinton, Obama, etc. is just to temporarily reduce the drama because they're all so frickin' tired at this point.
Some of it is genuine (between Hillary and Trump at least - they were friends!). I expect a lot of it is because they all really just want what's best for the country and realize that division is not the way forward.
From Trump's angle: as much as people liked chanting "Lock her up!" there is precisely zero chance that Trump does a thing about it. That whole thing is going to go away because Trump is going to have to make
some friends on the other side of the aisle. He won, and winning gracefully isn't that hard (though people do screw it up).
From Hillary's angle: she goes out graciously, knowing this is probably her final act. She knows she got beat, and she's smart enough to know
how and
why she got beat. Going out as a sore loser discredits her very real (and whatever your politics, very impressive) legacy.
From Obama's angle: Obama has as much reason to loathe Trump as anyone, especially given that Trump's stated mission is to essentially unravel Obama's legacy. But Obama's usually been pretty good about taking the high road in public, and is concerned enough about the future of the country that he probably just wants to get the healing process underway as fast as possible.