Bernanke the misguided:
Maybe he truly believes the words that come out of his mouth in these hearing - that the Fed is 'ready to act' as if it has anything it can do at all. What we've learned is that interest rates matter very little in these kinds of deep financial recessions, and even if they did, the Fed has already pushed even certain mid/long-term rates to record lows. Is it possible that Bernanke wants to believe that he can help and truly is just misguided. Perhaps, but I think the probability that he could be duped this easily is low.
Bernanke with the big ego:
Maybe he's fully aware that the Fed's actions are likely to do little to stimulate the economy but he wants to come off to Congress and the American people as someone with a lot of power. He wants to continue living in a fantasy where everyone hangs on the Fed chair's every word as if at this point it really means anything. I don't know the man personally, but again, I have a hard time seeing Bernanke being Mankiw-like in this way.
Bernanke the weakling:
At this stage in the history of economic policy, Bernanke has had opportunities to really take it congress, to really express what I must imagine is his and certainly the average Joe's frustration with the deadlock, vitriol, and general dysfunction that defines our legislative branch. He could talk about how the fiscal dangers are not of 'running out of money' but of failure of the public sector to invest in our future or to help the private sector rebound - leaving employment and with it tax revenues fairly stagnant. But instead he talks in low tones about 'fiscal cliffs' - he suggests no innovative legislative actions beyond maintaining the status quo (not letting tax cuts expire, and not reducing government-driven demand beyond current levels). In other words, Bernanke the weakling knows the only potential solution, if there is one, lies with the legislative and executive branches, but he is too scared to push the point. This sounds like an academic economist - someone who is good at numbers but not good at message. Could this be the real Bernanke legacy?
I've been assigned to focus on maximum employment and price stability, not to hold threats over Congress’ head. Congress is in charge here, not the Federal Reserve.
I don't know if it's his 'job', but it seems like the right thing to do for the country.