slowly I turned, twitter by twitter... closer, and closer.

Trump’s tweets are injurious to Trump’s legal position regarding the possible underlying crimes (i.e. paying off former 'affairs') and obstruction (e.g. tweeting false statements).

Trump can't invoke the Fifth Amendment protection against self-incrimination, his public statements have now waived that right.

He cannot refuse to talk under oath if he has talked about it openly.

Michael Cohen (and perhaps others) contradict him.

Trump’s tweets reinforces the need for Trump to be questioned about ongoing legal proceedings.

He has expressed a judgment about key facts: (1) Trump’s loquaciousness on Twitter (not to mention his golf outings) also make it hard for attorneys to argue that he cannot spare a moment to talk to the prosecutors.

In short, Trump really cannot contain himself. That’s the very reason his lawyers cannot stop him from incriminating himself in tweets.