His comments about California are not only unhelpful but, ignorant to the facts regarding the state's water supply, how it is used and the tragedy that besets California due to a chronic high-pressure system that causes all these problems.
Trump makes his nasty comments in anticipation of having others correct him. Then he has not only popular belief before him, but, facts from well-informed citizen activists that sincerely care about California, it's people and culture. I have no patience for his form of political governance. A real president would have ready information available from NOAA and NASA and already engaged in a conversation with Governor Brown. Governor Brown knows California. It is an enormous state and it's economy vital to the USA and the world. There is no one in the USA that knows California as does Governor Brown.
The USA needs a president that cares and is educated to know what governance is. Donald Trump is intent on destroying the federal government in three years time. Sounds like a Russian invasion to me. Why bother educating Trump at all? He doesn't care about the country, he wants it destroyed.
Trump is an ignorant billionaire that achieved his monies by bankrupting others. He isn't a leader. He is an abomination to the USA and the global community.
He chronically states hateful and horrible statements because he is ignorant, not because he is learned.