Because the man of whom he is most jealous and envious CREATED it via Executive Action. The trump will die trying to eradicate it and anything Obama accomplished.
That is the only reason he pulled out of all alliances that Obama joined thus jeopardizing our security and standing in the world. We are no longer partner or leaders to look up to. We are withdrawers aloners isolated from everyone to please the trump and we are seen as absolutely untrustworthy and undependable kibitzers. Who needs that? Who needs us? Well we do provide entertainment as a constant laughingstock but tinged with horror.
The trump will go to any lengths to erase Obama from our collective memories. He doesn't care what it takes.
Old dog gnawing on old bone. Forever. Until death them do part. SIGH