Even Republicans seem to be conceding that, as reported here and elsewhere a few weeks ago, the Senate will go along with the House and include reconciliation instructions for health care. Assuming all of us are correct, it means the Democrats will have the ability to pass health reform with just fifty votes, if they choose, rather than the sixty required to break the inevitable filibustering by Republican opponents.

It's hard to overstate how radically the reconciliation option would shift the dynamics of debate. It's not just that it would make passage of a bill more likely. It's that it would utterly redefine the conversation.

Put yourself in the shoes of a health care industry group--say, for example, the insurance industry. You probably have the power to swing at least a handful of senators your way, through advertising, astroturf organizing, and direct lobbying. If it's sixty-votes-or-bust in the Senate, reformers will probably need those senators to pass a bill. That means you have enormous leverage. You can hold out for the best possible deal and, barring that, simply walk away.

In other words, you know that there will eventually be two options on the table. A bill you like or no bill at all.

Now imagine Democrats have the option of using reconciliation. They need just fifty votes, which means they may not need your support after all. If you demand too much, they may just ignore you altogether--and craft a bill, perhaps with the help of more cooperative lobbyists, that is not in your self interest.

In this scenario, there are three options on the table. A bill you like, no bill at all, and a bill you really hate

So what do you do? Chances are, you concentrate a lot harder on trying to get that bill you like.

And, in fact, that's happening already. The big interest groups that have traditionally fought reform--not just insurers, but drugmakers, providers, and employers too--have been pushing for some kind of legislation. Publicly, they're saying all the right things about the importance of reducing costs and expanding coverage. Privately, they're continuing to meet with lawmakers to discuss their ideas.

Case in point: Earlier this month, an official at one traditionally conservative group--a group that fought the Clinton health care bitterly in the early 1990s--said that the group is now lobbying Republicans to stay at the negotiating table and ignore pleas, from the hard right, to walk away. Partly that's because the group's attitude on reform has genuinely shifted. But partly that's because the prospects of a very unfriendly bill seem greater than ever before.

None of this is to say reform is even close to inevitable. (It isn't!) Or that a lot of those interest groups won't come out fighitng reform anyway. (They will!)

And there's a whole other argument to be had over whether, given the political compromises that come with bipartisanship, a reconciliation bill might be altogether better on the merits.

But reconciliation is a game-changer. And the interest group community knows it.

--Jonathan Cohn