What may finally consume the House Republicans is their boundless contempt for the American public — a contempt bluntly demonstrated in their refusal to consider any reasonable compromise with President Obama to avoid the so-called “fiscal cliff” Dec. 31. They know from the election results (and every poll) that the public believes taxes should be raised on the wealthy. They know that the public wants bipartisan compromise. And they know that the approval rating of the House Republicans, in contrast to the president’s upwardly trending numbers, are veering toward historic lows.

Moreover, they claim to believe that the major tax hikes and spending cuts that will occur on Jan. 1, if negotiations fail, will be ruinous for the American and perhaps the world economy. (And never mind that this concern validates Keynesian economics, flatly contradicting their professed ideology.) Failure to achieve a deal may result in a renewed recession or worse.

Yet the majority of Republican members adhere so blindly to their far-right ideology that on Thursday evening, they humiliated their own leadership by refusing to support Speaker John Boehner’s “Plan B” — and effectively scuttled negotiations between the House leadership and the White House. Boehner thought a bill to increase taxes only on households earning more than $1 million annually would pass the House, as Majority Leader Eric Cantor confidently announced. “We’re going to have the votes,” he said on Thursday afternoon. Several hours later the House leaders cancelled the roll call on the tax bill, admitting that they didn’t have the votes.

This embarrassing episode — the “Mayan Apocalypse” of the Republican Party — demonstrates again why it is unfit for the responsibilities of national office.

The Republicans proved their unfitness the first time in the summer of 2011, when they held the national debt ceiling hostage, supposedly to reduce spending, and succeeded only in damaging both the nation’s credit rating and the economic recovery. Now they have declared their unwillingness to negotiate with a newly re-elected president, who won easily on the taxation issue. Although they held the majority, they actually lost seats and received fewer total votes than the House Democrats. But still they see no reason to deal with the president or acknowledge the national consensus.

Naturally, public anger at the Republicans is growing. But how furious would people feel if they fully understood this latest absurd episode on Capitol Hill? Boehner’s proposal was exceptionally generous to the wealthiest taxpayers — and mean to the poor and working families.

His Plan B would have extended the Bush tax cuts for their first million dollars of income; repealed a limit on tax deductions by the highest-income households; established a dividend tax rate of only 20 percent; and maintained an estate tax break for those same highest-income families worth an average $1.1 million. At the same time, according to the authoritative Center on Budget and Policy Priorities, Boehner’s bill would have ended various tax credits for low-income and middle-income families, costing them roughly $25 billion a year and driving millions of American children into poverty.

But awful as that proposal was, it was deemed too liberal by the dominant faction in the Republican caucus. They found it so offensively decent, so treasonously moderate, that they made fools of their own leaders and themselves rather than let negotiations continue. (Their spending bill was even worse.)

The president is fortunate in his opposition, whose obstinacy and extremism may yet prevent him from making a terrible deal to damage Social Security or Medicare when neither is necessary. He wanted to make a deal — very badly — but there is nobody with the competence or sanity with whom to make a deal, not even a raw deal.

Now Obama must explain clearly what has happened. Perhaps then voters will begin to draw the obvious conclusion — that this country’s problems cannot be addressed, let alone solved, until they remove these Republicans from power.