The thing is though, the stimulus plan isn't known as the 'Congressional Stimulus Plan: it's commonly referred to as "Obama's Stimulus Plan". OBama is intimately associated with the plan, far more than the actual writers, and so if the cartoon is going to be referring to anyone,the obvious target is Obama.

But this is also a large part of the different perceptions I was talking about. If one isn't sensitized, if one isn't used to the historical usage of monkeys as a racial slur for African Americans, then the cartoon may simly look odd.

I'd say that without the racial context the cartoon looks weird; with it, it looks menacing. And a large part of that difference is going to be which context you've been exposed to.