Well, Hitler really did not like black people (African, African American, Caribbean, Hispanic, Indian, Middle Eastern...all non-whites were pretty much the same to him), so in terms of their opinions on race, they probably would have nothing in common. In fact, since Obama's interracial background reflects a pollution of a caucasian bloodline, Hitler would likely refuse to sit in the same room with Obama out of disgust.
On the other hand, if you remove Hitler's racial agendas and apparent insanity, you have his socialist philosophy, where Obama and Hitler have plenty in common. In Germany and throughout Europe at that time, there were a lot of Jews who came from old money. Their ancestors had been bankers and merchants who had taken advantage of the fact that Christians were not allowed to charge each other interest on loans. As Hitler was gaining influence, he used a lot of class-warfare rhetoric, blaming the depression on those who still had money. He also simultaneously made promises about getting everyone jobs, healthcare, education, and so forth. In order to stop violent crimes, he asked all citizens to "willingly" relinquish their weapons to the government. The Jews were rounded up and sent to ghettos not to punish them for being Jewish but because they needed a place to live while their possessions were sold and the wealth redistributed to curb the depression. The disabled were sent to facilities where they could be cared for in ways their families could not manage, which actually meant they were used in medical experiments until they died. Everyone was given a job, even women who had previously stayed home with their children. Childcare and education were free.
In short, a picture was painted to deceive the Germans into thinking their needs were being met so they would not see the true cost of those needs. I am not proposing Obama has a secret agenda to kill a specific group of Americans, because I really don't know what secret agendas he may or may not have. What I do know is that he is making a lot of promises that have a very high cost, and he doesn't seem capable of telling us how that cost will be covered.