The tweet was up for four hours! People pointed the "white power" part out right away. The president is always reachable by his people, by definition. It was more than a smoking gun.

No apology or explanation from him, not even an "oops." Here's the video Trump posted: https://www.youtube.com/watch?v=Wibk3QsT7-M

There's not much ambiguity there. Thanks to others for finding the link.