The irony of this meme is that the real threat to America is not, as suggested, President Obama. The real threat comes from the people who produced it.
If they really believe that President Obama is similar in character and intent to those dictators, these people have serious mental health issues that require attention. People who experience such delusional and paranoid reasoning are a threat to themselves and their communities.
On the other hand, if the creators of this photograph in fact know that the message is not quite accurate and are using sensational propaganda to scare less sophisticated people who emotionally depend on their guns for a sense of protection, they are telling us quite succinctly that neither their character or ethics should are trustworthy.
Isn’t this exactly the kind of dishonest, manipulative propaganda one would expect to be employed by supremacists who reject democracy when they can’t be bothered navigating the democratic process?
(Thanks to my cuz Dr. Joel David for sharing this meme with me.)
Tent of Abraham 
Meanwhile in most of Europe… No arms or mass murder…