As Philip Klein noted this morning, The Obama campaign’s Big Bird ad shows how far Obama has come since he spoke lofty rhetoric about the nature of our politics when he launched his campaign in February 2007.

What’s stopped us is the failure of leadership, the smallness of our politics — the ease with which we’re distracted by the petty and trivial, our chronic avoidance of tough decisions, our preference for scoring cheap political points instead of rolling up our sleeves and building a working consensus to tackle big problems.