Why is Obama slamming Trump for sending troops to the border despite doing that same thing himself?

I'd have to heard the context of that statement

You are a retard

Obama is filled with hypocrisy and bitterness since his so-called Obummer Care is being dismantled.

Maybe because Trump is lying about the reason he is doing so? Maybe because Trump is using my tax dollars on a political stunt? I can think of several other reasons but those were enough to get me to vote Democrat even before Obama mentioned them.

My president should be someone I would introduce to my wife and children. Donald Trump is not.

Trump is using our troops as a political stunt. Obama wasn't a doofus clown.

I don't recall Obama sending troops to the border as a political stunt. Is that one of those "alternative facts" I've been hearing so much about?