Adendum
The American constitution should be amended so it is easier to remove a president from office.
The US constitution is built on the premise of three branches of government (the executive, the legislature and the judiciary) that provide checks and balances. Thus, at the moment, it falls on congress (the legislature) to remove a wayward president. Unfortunately, it assumes that two out of three of the branches will act in the best interests of the country. This is not the case at the moment. The executive is controlled by a psychopath. The upper house of congress is controlled by a partizan hack and between them they have conspired to stuff the judiciary with more partizan hacks.
If it were any easier to remove a president from office, the USA might get into a position where a partizan congress could remove a president of the opposite stripe at will.
If Trump carries on the way he is doing, I suspect someone will take it into their own hands to remove him permanently using a gun. If that happens I think there would be more cheers than tears.
The US secret service is very experienced at stopping that sort of thing from happening.