A few smart people I know have responded to my TRB column about liberal disappointment the same way, which means I didn't make the point clearly enough. In the column, I noted that liberals have turned against literally every Democratic president of the post-war era. The response I've heard is that the disappointment was warranted in this case or that -- Jimmy Carter, Lyndon Johnson, Bill Clinton especially.
I mostly agree. My point is not that Jimmy Carter was a good president, or that liberals had no good reason to resent Lyndon Johnson. What I'm saying is that, if you're a liberal and you think every Democratic president is a disappointment, then you need to recalibrate your expectations.
I have to agree with Chait here that our expectations have to be recalibrated. A decent expectation for a new Democratic President would be a second-term Bill Clinton--a moderate but progressive leader who knows how to fight conservatives and is able to win constant incremental change, all the while preserving past progress. To me, that should be the bar. I'd say that Carter falls below it while Obama exceeds it palpably, as does Johnson despite some rather gross missteps. But setting the greatest president of the past 145 years as your expectation is a recipe for disappointment, and so much of what Roosevelt accomplished was just so sui generis--a once-in-history combination of man and moment that frankly will never recur.