Via Wall Street Journal:
No President is responsible for all of the views of his appointees, but the rise and fall of Mr. Jones is one more warning that Mr. Obama can't succeed on his current course of governing from the left. He is running into political trouble not because his own message is unclear, or because his opposition is better organized. Mr. Obama is falling in the polls because last year he didn't tell the American people that the "change" they were asked to believe in included trillions of dollars in new spending, deferring to the most liberal Members of Congress, a government takeover of health care, and appointees with the views of Van Jones.
Read the whole thing, it is worth the read.
Obama knew damn well who he was giving control of billions of dollars to, he knew and it was fine by him as long as the public wasn't quite aware of what Van Jones stood for.