A mountain of stuff could be said here - but time does not allow me. I take your point about the 2008 election and coming to power through popular consent. Perhaps your view will prove out - I have always been hesitant to equate our prez with Stalin, and there is no perfect fit either way.
I do think you have over-simplified Stalin's rise to power. Lenin saw Stalin and his ambition, as well as his ?narcissism - perhaps thirst for power. He confided to those close to him that he was wary of Stalin [perhaps analogous to Bill Clintooon and the 'bamster.] Lenin died of declining health, and while there is NO historical evidence that Stalin had a hand in Lenin's death, I would not be shocked if such evidence should emerge.
Stalin did not assume Lenin's office directly; he took the position of Communist Party Secretary and manipulated that office into one of dictatorship... he would attack and replace Party officials - not as head of state but as Party leader.
None of this bears directly on my premise. My view is based on Stalin starting out as a narcissist - in my opinion - and then as he aquired power he became more and more addicted to it and wary of anyone who might threaten that power - viz: Trotsky... Kirov... most of the old Bolshevics... the babushka who swept the trash from Red Square... etc., etc.
For whatever reason, people came to adore Stalin - or avoid him, and the Cult of Personality was born. I see the Cult of Personality developing now - if you are in opposition your are seriously flawed and must be singled out from the populace. Meantime Stalin knew how to present himself as a lovable person - Pappa Joe - who only wanted what was best for the Union.
Well, there... now I have gone and dug a bit deeper despite time constraints. :^/
My comment went as much of more to the tactics of Obama, than to his personality. He employed the psychological manipulation tactics of Hitler. (But, of course, although Obama is not the dolt that some people claim, he is certainly not in the same class as either of the pair, under discussion.)