And this was an offer, not a deal. Are we about to see another round of the president negotiating with himself, snatching policy and political defeat from the jaws of victory?

Well, probably not. Once again, the Republican crazies — the people who can’t accept the idea of ever voting to raise taxes on the wealthy, never mind either fiscal or economic reality — have saved the day.

We don’t know exactly why Mr. Boehner didn’t respond to the president’s offer with a real counteroffer and instead offered something ludicrous — a “Plan B” that, according to the nonpartisan Tax Policy Center, would actually raise taxes for a number of lower- and middle-income families, while cutting taxes for almost half of those in the top 1 percent. The effect, however, has to have been to disabuse the Obama team of any illusions that they were engaged in good-faith negotiations.

Mr. Boehner had evident problems getting his caucus to support Plan B, and he took the plan off the table Thursday night; it would have modestly raised taxes on the really wealthy, the top 0.1 percent, and even that was too much for many Republicans. This means that any real deal with Mr. Obama would be met with mass G.O.P. defections; so any such deal would require overwhelming Democratic support, a fact that empowers progressives ready to bolt if they think the president is giving away too much.

As in 2011, then, the Republican crazies are doing Mr. Obama a favor, heading off any temptation he may have felt to give away the store in pursuit of bipartisan dreams.

And there’s a broader lesson here. This is no time for a Grand Bargain, because the Republican Party, as now constituted, is just not an entity with which the president can make a serious deal. If we’re going to get a grip on our nation’s problems — of which the budget deficit is a minor part — the power of the G.O.P.’s extremists, and their willingness to hold the economy hostage if they don’t get their way, needs to be broken. And somehow I don’t think that’s going to happen in the next few days.