personal failures. If anything, I would NOT be surprised if his go-between is furiously lobbying Xi to help him and not to respond in kind. 

If he is contemplating a re-election bid, he would need China to co-operate and work with him more than ever. He would only truly attack China if he is giving up and admitting defeat in the November election and decides to take a suicide run at China. All these escalations are just smoke and mirrors. Just look at how much teeth in the sanctions against Hong Kong.