I think you are confused about the meaning of the word dictator. Dictator is not the same as absolute ruler. Nikita Khrushchev, Mubarak, Leopoldo Galtieri, Joao Batista Figueiredo and even Pinochet were all dictators, but they did not hold absolute power over their countries. That does not not make them less dictators. So your argument that Obama is not a dictator because he could not just shove a universal health care system through congress is not valid.
Now, I was born and lived a good part of my life under a dictatorship (not an absolute rule), so did Bajo_Cero and maybe even Matias, if he is old enough. So I think I have some first hand knowledge of what makes a dictatorship. The reality is that the central pillar of a free society is the right to due process. It is the certainty that the ruler cannot simply imprison you or kill you at whim. That any charges placed against you would be presented before a jury made up of your peers and them and them alone would determine guilt and punishment. This is something that started with the Magna Carta in England back 1215 and later much expanded under the 4th amendment of the US Constitution. It is known world wide as the right of habeas corpus and the right of due process. When Brazil, Argentina, Uruguay and Chile became free societies, the pivotal moment that marked that transition was not the re-establishment of free speech and freedom of the press. No, the marking point, the critical moment that signified the return of freedom was the re-enactment of habeas corpus and the right of due process. That is the fundamental element that separates a free society from a dictatorship: The certainty that the government cannot spy on you without a court order. The certainty that the government cannot simply grab you at some dark corner at night, throw you into a forgotten cell somewhere and throw away the key. The certainty that you have the right to be charged with a crime, have your day in court where you can face your accuser and the evidence against you, and be judged by a jury of peers.
Americans today live in a country where those rights have been publicly nullified. With the Patriot Act and the NDAA, Obama can kill ANY of us, anywhere, at his discretion and all he has to say, if questioned, is that he determined that you were a threat to the United States and he had the authority to kill you. All other information is classified. That is it.
Or while driving home, you can be pulled over by a NSA car, have a bag put over your head and disappear, being locked up on some forsaken brig somewhere. You don't have the right to a phone call, or a lawyer, or to notify your family. You just vanish. Your family may wonder where you are and have the local authorities go look after you. Eventually, if the local authorities start making progress, they might be contacted by the Dept. Of Homeland Security and told to suspend the investigations. They can also be placed under a gag order not to disclose to your family or anyone why they had to stop the investigation. What I am describing here is not some dystopian sci-fi scenario, this is the USA today. Now, you might claim that other presidents did this before. I am not aware of Ford, Carter or Reagan ordering anyone to be assassinated. If they did, they did so covertly and in a very clandestine way, because they knew that what they were doing was highly illegal and they might face impeachment or even criminal charges if caught. Obama did something unprecedented in American history, he publicly nullified the 4th amendment of the US Constitution. Today, the POTUS can, at his discretion, kill and arrest ANYONE, at ANYTIME that he arbitrarily labels an "enemy of the United States", including American citizens. The frequency in which he may or may not exercise such power is irrelevant. The power exists and he can exercise it anytime he damn wants it. You may call this being weak president, being a disappointment, being corruptible or any other type of lipstick that you want to put on a pig. In Brazil we call it dictator.