Prisoner's Dilemma?

Why did the bailout fail? What Do the Data Say? says it was because of collusion, and an incentive to cheat. Specifically,

My initial guess is it's the classic problem of collusion. Everyone agrees to do something, in this case to vote "Yes," but everyone has a political incentive to "cheat" and vote "No." If enough people cheat, then the legislation doesn't pass.

The blogger points us the Economist which suggests something similar did in fact happen. Crikey!