This was not a compliment. Trump adheres to the theory of unearned black privileges at the expense of white effort, that there is a hand-me-out meritocracy specifically for black people, a form of cultural welfare.
This made Obama an early target for Trump. He questioned Obama’s birth and his heritage, his abilities and educational pedigree. He questioned his leadership and his work ethic. Trump knew the terrible legions of flaws he possessed and was incredulous that this black man could be devoid of any.
So, he feverishly searched for error, sometimes inventing it, moreover projecting his own error onto Obama.
Obama became Trump’s foil for personal reasons of racial and cultural insecurity. But Trump’s view of him perfectly aligned with a larger phenomenon: A significant swath of white America grated at the uppityness of this black man who would set the tone for how Americans should behave, and his black wife who would lecture them about what to eat.