I'd add the meme of Obama in a "Buckwheat" like haircut with the KFC bucket and watermelon "campaininn" smacks of nothing but racist undertones. Not even. I've said since the beginning of Obama Presidency there is plenty of substance or lack thereof without having to bring half his geneology into the conversation.
I agree that there is plenty objection to Obama on Constitutional grounds that are independent of race, party or whatever.
However those images in using racial references intended to be hurtful towards race, such as the watermelon reference,
distract from the content of the argument, stoke the emotions, and incite backlash that makes the situation escalate worse.
The more ambiguous references, such as connecting Obama or Rice to "traditional" characters,
can be seen as either exaggerations by character OR by race, so this is even more contentious because the
protesters can be attacked for criticizing the racial associations when that isn't the only interpretation.
That reminds me of when Rush Limbaugh purposely used the term FARDING on the air,
got people upset, thinking he said FARTING, and then could argue it was their fault not his.
It is still baiting people to incite a negative reaction.
Yes, you can blame it on the people reacting, as the reason they see it as racist and say it's them.
But to be honest, for these exaggerations that "cross the line" the point is knowing it will incite them anyway, based on race.
When you point a rubber gun at someone, even though it's not a real gun,
if your intent IS to coerce them by fear it is a real gun, then you're still guilty of that intent.