The Trinamool Congress has announced withdrawal of support from the UPA,citing irreconcilable differences over FDI in retail and aviation,fuel pricing,the pension bill and other issues. TMC ministers will resign on Friday. Assuming there is no rolling back or rolling over,this is a moment of clarity. The UPA has lost its last excuse. If it can lean on one of the other sizeable regional parties,the SP or the BSP for support,this decision is unlikely to destabilise the government. And in fact,Mamata Banerjees departure may mean that internal resistance,real and imagined,has largely dissolved for the UPA. The prime minister can no longer offer coalition compulsions as a reason for inaction. His government must exert itself fully in the time it has left. The UPA has ended up offloading one of its biggest problems,and found itself with room for improvement in the six ministerial berths the TMC will vacate. The railways,for instance,has long needed to be rid of the TMCs erratic and incompetent grip. TMC ministers were conspicuous mostly by their absence and prioritised Banerjees whims over the UPAs needs. Their leaving the government now is no worse than their being inside it while remaining unpredictable and undependable on high-stakes issues. From land acquisition reform to the railway budget,from FDI in retail to fuel pricing,Banerjees views have always been at odds with the rest of the UPA. She took her grouse over the presidential candidate to Facebook. She embarrassed the government by dropping out of the prime ministers delegation to Bangladesh,after she developed a dislike for a long-planned Teesta water-sharing arrangement. It is also true that she has been the convenient excuse for a listless,uncommunicative government. Now that Banerjee has walked out of the space of perennial rebel,the UPA will have to deal with other players and their demands. It will be a delicate balancing game,requiring patient negotiations and hard bargains. But it may be more manageable,in as much as the house is not being pulled down from within. Meanwhile,this has also been an object lesson in the perils of striking a maximalist pose. Like the Left before,Banerjee has staked everything on one set of issues,denying herself wiggle room. This time,her political options are severely constrained she cannot afford to be seen with the BJP,and with the opposition to the UPAs economic decisions converging around the Left,Banerjee may have just painted herself into another corner.