I'm not sure the historical record supports your contentions, Saz.
Obama tried on a number of occasions to close down GB. Congressional Republicans opposed him, and made it virtually impossible for him to address the issue in a sensible way. He issued an Executive Order to close GB within a year and then presented a plan to Congress, with some going back to Middle Eastern countries, and some to be moved to the mainland US. This was shutdown and opposed, like everything else he tried to do in office. You could argue that he pursued this knowing it would fail - which is reasonable - but that doesn't necessarily mean he didn't genuinely support the measure.
Supporting GB is a declaration of moral and political depravity. I'm usually more interested in pragmatism than principles, but in this case, the precedent created and the realities of the prison make it impossible for any rational person to support its continued operation. I'm not surprised to see you support it, because you are genuinely amoral, but for a large chunk of the American population, it is a terrible affront to American values, and a massive stain on its reputation. That stain is only going to grow under a President who openly supports torture and illegality.