(Evan Vucci/AP Photo)

Until today, the story of this tea party Congress has been one of House Republicans digging in on big issues and forcing President Obama to make major concessions.  They did on the government shutdown showdown in the spring.  They did on the debt ceiling showdown over the summer.  They did it even before they were sworn in, forcing the president to accept the extension of the Bush tax cuts last December during the lame duck session of Congress.

Today:  A major shift.  House Republicans, for the first since the 2010 elections, dug in on a major issue only to end up folding.

MAINBAR: House Republicans Cave on Payroll Tax Cut

On Tuesday, all but seven House Republicans voted to reject a temporary extension of the payroll tax cut.  In press conferences on Wednesday and today they dug further, insisting that a temporary extension was unacceptable.

What happened?

House Republicans were losing the public relations battle and losing badly.  They took a stand against a bill that passed overwhelmingly - 89 to 10 - in the Senate.  It was a bill that even tea party conservatives like Sen. Marco Rubio, R-Fla., and Sen. Mike Lee, R-Utah, supported.  House Republicans stood alone in opposing it.  It became clear that if taxes went up on Jan. 1, House Republicans would take the blame.

By Wednesday, even members of the freshman class were getting antsy.   Earlier today, Rep. Sean Duffy, R-Wis., a poster child of the 2010 tea party class, called on Republican leaders to immediately pass the two-month extension, saying "Middle class families deserve a Congress that will rise above the squabbling and ensure their taxes don't go up right after Christmas."

One final note:   Even as House Speaker John Boehner, R-Ohio, was publicly taking a tough line Wednesday, I wrote a blog predicting Republicans would cave within 24 hours; 26 hours later, they did.