One of the more interesting strategic challenges the Obama campaign faces is this: How can he get voters to understand the depth of the economic challenges he inherited when he took office without appearing to blame his predecessor for what happened on his watch?

It’s a delicate balancing act, and whenever Dems come out and say Obama is responsible for the economy, it’s big news. It was news when DNC chair Debbie Wasserman Schultz said Obama and Dems “own” the economy, and it was news when Joe Biden did the same.

Now the President himself has said it. The key moment came during Obama’s interview with WCCO-TV in Minnesota, video of which is right here. Asked at what point the economy becomes his fault, and not his predecessor’s, Obama said:

Well, it’s always my responsibility. I’m less interested in allocating blame than just making sure that we’re taking every step we need to to move the economy forward. And traditionally, after big financial crises like this, the economy takes a longer time to heal. And we’ve seen some progress in the private sector, where we’ve seen over two million jobs created, and this year alone over a million jobs created. But it’s just not enough yet to have an impact on everybody who needs help out there.

My understanding is that the Obama team trusts polls that show Americans still blame Bush more than Obama for the economy; there’s no reason for anyone to come right out and say it. The trick is to call attention to the fact that a severe crisis was in fact dumped in Obama’s lap — to persuade Americans that his policies couldn’t possibly have solved it as quickly as they’d like — without giving Republicans an opening to question his leadership by claiming he he wants to dodge responsibility for his failure to fix the crisis fast enough.

Indeed, in that same interview, Obama added: “Keep in mind, when I came into office the economy had contracted by 9 percent, which is the most since the Great Depression.”

The careful balance Obama needs to strike is to embrace responsibility for Americans’ current suffering, while simultaneously blaming Republicans for failing to act to alleviate that suffering and convincingly drawing attention to the monumental scale and severity of the mess he inherited from them.