I think that the president of PRC has a better chance to harm Bitcoin.

Please correct me if I am wrong (and I mean it, cause I am not 100% certain of this).

So, imho, if China decides to shutdown their internet or disconnect it from the rest of the world, then most Bitcoin miners will be cut off.
Until the network will adjust for that it takes quite a number of days - I don't know how it's calculated - but for some while the transactions will be VERY slow.
If this will take too long (which is a relative term) this would harm the network a lot and some may / will leave it.

Now, after the difficulty dropped this much, the Chinese have a chance that at the point their network is back to even do a 51% attack. Though unlikely since it's bad for business, this still can happen, theoretically.



Of course, I may be in a big confusion, somebody should check this theory against the possible reality.