As the smoke clears this morning, the recriminations from some on the left are fierce: The debt deal represented total surrender by the President, who has now legitimized the GOP’s extortion politics as an acceptable means of governing. More surrenders, they predict, are surely going to follow.

Paul Krugman makes the most aggressive version of that case I’ve seen this morning, arguing that Obama repeatedly sidestepped opportunities to change the dynamics of the situation. Krugman says Obama could have aggressively used the bully pulpit to demand that the GOP hike the debt ceiling early on, and that he could have threatened other legal means of hiking the debt ceiling, if only to increase his leverage.

Jonathan Cohn agrees, though he allows for the possibility that a different approach might not have gotten anything more:

Why didn’t he demand Republicans raise the debt limit, the way Congress has routinely for previous presidents, and stand by that when Republicans inevitably refused? Why didn’t he spend more time criticizing Republicans for their values and priorities rather than trying to find accommodations with them? Why didn’t he play up the possibility of the 14th Amendment, if only to increase his leverage? Imagine if the president had, from the very beginning, laid out a few key principles and stuck to them: No tying the debt ceiling to deficit reduction; no attacks on Medicare, Medicaid, and Social Security; no deficit reduction without higher taxes on the rich.

No, I can’t be sure he would have secured a better deal.

I agree with all of this. I wish Obama had done all these things. That said, an additional question needs to be posed. If the basic premise of this critique holds that Obama should have stood up to a party that was prepared to allow the economy to implode in order to get its way, then why are we assuming that Republicans wouldn’t have done that anyway, no matter what the President did? If Obama had barnstormed the country for weeks, hammering the GOP with the demand for a clean debt ceiling hike and threatening the Constitutional option if the GOP didn’t buckle, would Republicans really have changed their behavior?

There are a couple of nuances that need to be added to the criticism of Obama, even though much of it is fair. First, with the deadline looming, Obama and Dems faced a choice: After their demand for a debt ceiling hike was rebuffed, they had to decide whether to shift to negotiations. Given that the deadline was fast approaching, this had to be done earlier rather than later to ensure that a compromise could be reached.

Could Obama have adopted a far more aggressive posture while negotiations were going on? Absolutely. But the simple fact of entering into talks inevitably reinforced the sense that Obama and Dems were not prepared to allow default — no matter what — reinforcing a set of dynamics that were stacked against them. Was that avoidable?

Second, while critics such as David Frum are right to argue that there is plenty more Obama could have done to rally the public to pressure Republicans, it’s important to note that Obama and Dems did win the P.R. battle. Multiple polls showed strong support for compromise; they showed a decisive shift towards the notion that failure to raise the debt ceiling could be catastrophic; they showed the public would blame the GOP for failure. Yet that didn’t stop the GOP from allowing the threat of default to linger, even as it upped its demands. If Obama had done all the things Frum and others advocate, would public sentiment have been so much more skewed against Republicans that they would have to cave? I don’t know. Again, the starting premise here is that they were extortionists. Hostage-takers aren’t known for caring what other people think. It may simply be that the dynamics of the situation were insumountable: Obama and Dems were not prepared to let the country default no matter what. Were Republicans prepared to allow the country to default? We can’t know — but Obama plainly decided he didn’t want to take the risk of finding out.

Again, I want to stress that I wish Obama had done all the things critics say he should have done. Why didn’t he? Was it a political decision to project a desire for compromise at the outset to win independents? Did he, as Jonathan Chait argues, seriously misjudge opponents? I tend to think Obama sincerely decided that a more table-pounding approach would have been counter-productive. That’s who Obama is. Whatever the reason, we simply can’t know whether a more aggressive approach from Obama would have changed the basic dynamics of the situation or resulted in a better deal.

But it’s precisely because we can’t know that I hope he will do things differently next time, perhaps when the battle rejoins over the expiration of the Bush tax cuts — a fight which, if he wins, will make the current deal far better. The current dynamic just has to be changed somehow, because it’s untenable.