The Tea Partiers "won" on the budget, as Ezra put it, because they screamed and yelled and wouldn't compromise and threatened to primary everybody to the left of Genghis Khan. The Republicans cut even more than they had before, and then "compromised" with the Dems back to their original desired position.
The lesson should be obvious for the "reasonable" Democrats that folded like a cheap suit from 2008 to 2010. It should be even more obvious for "reasonable" so-called "progressives" that just went along with the ride for the sake of a party that, like or not, couldn't give a rat's ass about them.
Yet, for all that, I suspect not a soul will figure it out. They haven't yet. Why would they now?