Just a moment to create a side-by-side comparison
Note that Rockwell's juxtaposition of the little girl (all in white) against the background of graffiti and thrown tomatoes makes a clear statement as to the contrast between the violence of the segregationists and the innocence of their target. It's subtle, well designed and beautifully executed. The Obama-as-Christ painting makes no real statement beyond the idea of Obama as savior, unless the artist had intended to imply that he was being crucified on the presidential seal, in which case, his persecutors were the American voters. It's a sloppy thought, poorly executed (the pallet is garish, the composition is poor and the use of the crown of thorns is overkill). It's one step above van painting. For an example of how a great illustrator would handle an iconic image of someone that he saw as heroic, here's Rockwell's Saturday Evening Post cover commemorating Lindbergh's Trans-Atlantic flight:
I think the artist meant to compare Obama to Jesus. I'm not sure why he wants to do that, my guess is that it's more of a use of crucifixion imagery in the same way John Lennon did in the song "The Ballad of John and Yoko" ("The way things are going, they're going to crucify me"). Implying, of course, that someone is trying to crucify Obama in a figurative sense.
I don't worship the image of God, I worship God, so on that level I don't find the image blasphemous.
I'm not sure if the artist meant to equate Obama with God, even though I can see why such a work would be interpreted that way.
Unfortunately, the word crucify (and the associated imagery) has been used in these times to denote persecution of some sort (even imaginary persecution). That's why I used the Lennon song as an example, because I don't think that the roadblocks to the marriage of John and Yoko really compare to the bloody, horrific execution of an innocent man. It's hyperbole.
I think the artist was more trying to imply that Obama is somehow being figuratively crucified (by republicans/FOX/etc.) than that Obama is equal to God. He also probably guessed that by producing a controversial work, he'd get attention.
The idea of Obama as some sort of savior was part and parcel of the PR campaign that got him elected. To many African Americans, he may have seemed that way. He may also have seemed like a symbol of grand forgiveness of America for its past racism.
Jamie Foxx's recent "lord and savior"statement must surely be taken in this context.
It's also worth remembering that even the media of the time was joking about Obama's "savior" status: