Paul Krugman nails it. He explains why Trump promoted Putin and Russia and advocated trade polices which do little for most Americans. Both of them have a contempt for democracy; they both prefer autocracy to democracy. My guess is that Putin could also end Trump's presidency if he chose to release information that he has about Trump and his campaign. He is in the catbird seat.
Krugman points out all of the economic ignorance displayed by Trump and his top economic advisers. They can get away with this nonsense because most of Trump's base has little understanding about these issues. They enjoy watching Trump act powerful and they may believe that his trade policies are in their best interest. They are primarily campaign slogans for an endless Trump campaign. He prefers campaigning to running our government