I don't think Donald Trump has mental health problems (at least not more than most), he has just tapped into a particular zeitgeist, rather like Nigel Farage has done in our little country. Neither do I think he is racist on a personal level. It's all about pandering to the electorate, or a particular section of that at a given time. When this is all over and Mr Trump goes back to doing what he is best at, we'll be able to see that clearly.
I think it would be quite a different matter if he eventually became President but I'm hopeful that will not happen.
Obama has been a great President, a tough act to follow. Yes, people are disappointed he hasn't achieved more but what president of the United States can push forward their ideology as if they stand alone? No president is completely independent. In all honesty, it night be very dangerous if she/he was. Obama has done well and will go down in history as a being a lot more than the first black person to hold the office, something most of us have virtually forgotten.
(Earlier on someone asked why Ad_O was not criticising Russia. Russia was not being discussed at that time which is as good a reason as any but do people think, because, eg, Ad_O is Orthodox, that he considers Russia to be above criticism? Ridiculous, like saying Anglicans can never say anything against UK.)