If you click through to the tweet there is a video of Trump disavowing Duke at the presser where Christie endorsed him.
Funny thing is that goes out to 6.5 million people (granted, that’s international) and if you include the retweets it’s probably much much more. The news media’s megaphone isn’t quite as loud
I get that Trump “disavowed” Duke. I don’t get why a couple days after he disavowed Duke he is saying he doesn’t know Duke, etc. Perhaps as others have said, it is to create controversy where there is none “hey - I disavowed him...”. I don’t think it can be chalked up to early signs of Alzehimers.