Slate did not include enough of the quote to get the larger context. They clipped of Obama making applause lines with the crowd listening that people who were successful did not get there because they worked had or were smart. Then he mentioned teachers and roads. Then he mentioned that people who owned business didn't "build that".
The difference is important. Obama was indeed saying that the success of the business owner was neither due to hard work nor to the unique talent of the business owner...and in FULL context there is no escape for the liberals trying to claim it was a gaffe.
...in FULL context there is no escape for the liberals trying to claim it was a gaffe. Add the derisive tone of voice, full of contempt for the business owner, and you there is no mmistaking precisely what he meant.
"out of context", my ass.