Give Speaker John Boehner credit for this much: His spin on the House’s refusal to extend the payroll tax cut is clever politics, even if it is untrue.

Boehner wants us to believe that the House is all for the extension, but wants to ensure it lasts the full year, not just two months, as in the Senate compromise. By this telling, the House is even more determined to get this done than the Senate.

Some will no doubt be fooled by that line. But the truth is that Boehner could not get his own caucus to fall in line behind the Senate compromise. When he presented it to his members, he was rebuffed by the conservative bloc.

Remember that the payroll tax cut has never been popular in Republican ranks. Several key leaders have spoken out against it. Of the eight members Boehner appointed to a conference committee to negotiate a deal, five are on record criticizing the payroll tax cut.

At its core, the Republican argument on the payroll tax is maddeningly hypocritical. They insist on preserving the Bush tax cuts, which reserve most benefits for the rich, without compensating spending cuts. But they will not tolerate a payroll tax cut, which mainly benefits the middle class, unless every dime is paid for with spending cuts. The party’s bias in favor of the rich has never been more obvious.

What to do? First, the White House and Senate Democrats will have to drop their hard line against further negotiations in the conference committee Boehner has in mind. If Democrats walk away, Boehner’s spin might just work. Americans who are tired of the partisan bickering are likely to blame both sides and walk away in disgust.

But in those talks, Democrats cannot let the House Republicans have their way by imposing cuts on the most vulnerable, or attaching noxious riders on environmental policy, as the House did when it passed a partisan extension of the payroll cut earlier this month. Yielding to that blackmail would reward them for this brinkmanship and strengthen the no-compromise faction of the party.

Yes, that means Democrats need to be ready to walk away without a deal. That would lead to higher taxes on the middle class, along with cuts in unemployment benefits and to Medicare doctors. All that would be a disaster for the American people and a fresh insult to the wobbly economy.

But we cannot allow the federal government to be hijacked by the most extreme and uncompromising members of the Republican House. This is a clarifying moment. If Boehner can’t control his radical caucus, then it’s time for Democrats to draw the line. Voters can then pick sides in November.