> Seems a strange and disturbing choice that the US public has made but their willl should be respected.

Sure. The US has, for now, chosen to adopt hostile immigration policies, which will incentivise international conference organisers to avoid it, like they do other countries with hostile immigration policies. I'm not sure where you see a problem?

> although the Google seems to suggest trump is currently looking good for reelection

Eh? How did Google do that?