Press reports are filled with expressions of optimism that the government shutdown and coming debt limit showdown will soon be resolved. Certainly many Republican senators, who hope to play a now-it's-time-for-the-adults-to-take-charge role in the crisis, are suggesting a deal is possible not only to end the shutdown but also to head off a possible default -- and it could all happen in the course of a few days.

The problem is, such a deal would be possible only if the conservative Republicans who have so far dictated the GOP's actions in the House are somehow taken out of the picture. Those Republicans have been unyielding in their demand that President Obama offer a concession imposing some significant new limits on Obamacare. And Obama has been equally unyielding in his refusal to offer any such concession.

That is an unresolvable conflict. And so far there is no sign it has changed.

A proposal by Republican Sen. Susan Collins that has been the subject of much discussion would include two proposals relating to Obamacare: 1) it would repeal the law's medical device tax; and 2) it would require verification that people who receive subsidies under Obamacare are actually eligible to receive those subsidies. Both have widespread Republican support, and in another set of circumstances would pass easily. But neither has been sufficient, at least so far, to satisfy the Republicans who originally sought to defund Obamacare, and later sought to delay it for a year, and then later sought to delay the law's individual mandate.

In their view, the entire Obamacare crusade has been about giving the American people relief from the health care plan's burdens and mandates. Neither element of the Collins proposal would do that. While they would be fine in any other context, the defunders were willing to shut down the government to stop, or substantially slow, Obamacare, and neither Collins proposal would do that.

But still -- given the pressures created by the partial government shutdown and the polls showing the damage it has done to the public's opinion of Republicans -- would Collins' Obamacare plan give the defunders a fig leaf, a way to say they stood up for changes in Obamacare and won? Probably not. The feeling among at least some of the defunders is that they have not come this far just to surrender in exchange for a fig leaf. And that is before one considers the big question of whether President Obama would accept any version of the Collins proposal in the first place.

So far, House Speaker John Boehner has deferred to the wishes of the defunders at nearly every significant point in the shutdown process. Most recently, he agreed to offer a clean, or relatively clean, debt limit extension that would avert a default crisis so that the fight over a continuing resolution that limits Obamacare could go on. If Boehner continues to show the defunders great deference, it is unlikely there will be a settlement soon.

The short version: If the defunders are still in control, there will be no deal. because when it comes to Obamacare, they would not accept anything Obama would offer, and Obama would not offer anything they would accept.

For there to be a deal, Boehner would have to say to the defunders: We tried it your way, it didn't work, and now we need to move on. There are plenty of Republicans in the House, not to mention Democrats, who would vote to go along with the Senate and pass a settlement of some sort. But for that to happen, Boehner would have to abandon the very people who have been most influenced his decision-making so far. So far, that hasn't happened.