Barry is using the propencity of Christians to feel bad about their past actions by dragging up actions that ended 140+ years ago.
This is to draw attention away from the actions of his 7th century cousins.
These are classic Bully and Muslim actions; Never mind what i`m doing, look at what yoooooou diiiiiiddddd!!!!.
Being surrounded by these stone age tribesmen, i`ve got used to their nonsense.
You hit the point of what Obama was doing. The real outrage is that he would use the Crusades and past slavery to justify the Barbaric actions of a murdering religion.
The actual truth is that Islam is not a religion of peace because their prophet participated in and encouraged forcing conversion by any means necessary. People are asked non violently one time to convert or die. If they do not, they die or pay a tax and live as a slave.
Now we know that all Muslims do not want to participate in the killing and violence, but they still remain in a religion that they know justifies the actions of ISIS or groups like Al Qaeda.
Obama is an angry man, most progressives are. They hate religion, particulary Christians because they feel it isn’t fair that anyone be judged for their behavior. In his mind, ISIS is the underdog.