CBO didn't think there would be a recession at all.

So far, the course of the economy the last 12 months has tracked closer to the predictions of the sorts of economists who are saying we need a much much bigger stimulus package. I'm not saying they are right either, but while CBO is solid and has very high integrity, they are quite conservative in the sense of using very standard sorts of models. If we have entered some sort of reinforcing feedback dynamic where a whole bunch of types of excessive leverage are all crashing at once, and causing pyschological effects that multiply the reality, then I wouldn't expect CBO to be the forecasters best able to capture that.

I really am trying to approach this as a social scientist and not a partisan. My read of economic history and theory is that the economy does sometimes hit discontinuities, frequently associated with bubbles and subsequent credit crises. What I see happening has me very dubious about regular macroeconomic models and very worried about there being a lot of downside risk.

That doesn't mean the current stimulus package is right in amount or approach. That I'm much less sure of. But I'd bet a week's beer that absent any policy changes, that CBO forecast would turn out to be optimistic.