It comes from a couple areas. 1. Obama himself (or his campaign) and 2. Obama supporters.
In the first case, Obama has a serious ego complex. They set up stages to present him like he's in a Greek Amphitheatre. In tons of his speeches they set the mic to have tons of reverb even when he's in tiny venues so he always sounds like he's thundering from above. Disagree if you want, but this video of his post-election speech shows he's got a really inflated opinion of himself. In his brain - before he came along sick people never got better. In his brain, he really was going to heal the planet, drop the ocean levels, yadda yadda yadda. The man really is an arrogant toerag.
http://www.youtube.com/watch?v=I0tuAJkbUWU
And then there what are called "Obama Zombies". A lot of them can be found just clicking around these very threads. To an Obama Zombie the man can simply do no wrong. No matter how blatant his lies are, they forgive them. No matter how inaccurate he is, they make excuses for it. No matter how badly he does, how much he screws up, or how inept Obama is on any particular subject they just keep licking up his puke and calling it nectar.
Now, that's just what partisan ideologues do on both sides so it is nothing new. But with Obama it has really gone to levels that are patently absurd. People like the "Obama Stash" woman, or the "Obama phone" kook - people that are just going around worshiping the man for no good reason - thinking that he's giving them money personally from his own stash. Crap like that.
So people who see Obama for what he really is can't help but mock this ridiculous Messiah-like complex that so many people are desperately tryint ot construct around him. Because - in the objective analysis - Obama is a small, petty, arrogant, mediocre twit of a man whose only real accomplishment to date is cramming an unconstitutional health care law through congress against the will of majority of Americans because he knows better than them (yet another example of his arrogance).