Considering the long history of portraying black people as monkeys, the amount of media publicity connecting Obama to the stimulus package, and the level of political awareness required to be a successful political cartoonist, I find it very difficult to believe this illustrator wouldn't have seen the racial implications in what he drew, not to mention however many editors this passed through before it hit the press. Even if he honestly intended to write a cartoon that only referenced the stimulus package and the chimp shooting, someone down the line should have stepped back and said, "you know, a lot of people are going to think we're calling Obama a monkey. Let's run something else."
It would be sort of like if Obama was pushing a produce-subsidation plan and they published a cartoon showing people being force-fed watermelons. You could print it and then say that no reference to race was intended, but why not make it peaches and avoid the whole ordeal?
Print publications everywhere are losing revenue to Web-based businesses. My guess is they figured any publicity is good publicity, and they knew this would get everyone talking. It'd be interesting to see if their sales have gone up since this started.