House Republicans are seriously entertaining dramatic steps, including default or shutting down the government, to force President Barack Obama to finally cut spending by the end of March.

The idea of allowing the country to default by refusing to increase the debt limit is getting more widespread and serious traction among House Republicans than people realize, though GOP leaders think shutting down the government is the much more likely outcome of the spending fights this winter.

“I think it is possible that we would shut down the government to make sure President Obama understands that we’re serious,” House Republican Conference Chairwoman Cathy McMorris Rodgers of Washington state told us. “We always talk about whether or not we’re going to kick the can down the road. I think the mood is that we’ve come to the end of the road.”

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Republican leadership officials, in a series of private meetings and conversations this past week, warned that the White House, much less the broader public, doesn’t understand how hard it will be to talk restive conservatives off the fiscal ledge. To the vast majority of House Republicans, it is far riskier long term to pile up new debt than it is to test the market and economic reaction of default or closing down the government.

GOP officials said more than half of their members are prepared to allow default unless Obama agrees to dramatic cuts he has repeatedly said he opposes. Many more members, including some party leaders, are prepared to shut down the government to make their point. House Speaker John Boehner “may need a shutdown just to get it out of their system,” said a top GOP leadership adviser. “We might need to do that for member-management purposes — so they have an endgame and can show their constituents they’re fighting.”

The country would eventually default if House Republicans refuse to raise the debt limit, which the Treasury estimates will hit in late February or early March. The government would shut down if House Republicans instead were to refuse to extend the law funding current government operations on March 27.

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Boehner assumes he can ultimately talk members out of default, but he is so wounded and weakened from last month’s tax-hike battle that the speaker might very well be wrong. Obama assumes Republicans would never be so foolish as to put the economy at risk to win a spending fight. Conservatives say he’s definitely wrong on that score. They say he’s the foolish and reckless one for piling up $6 trillion in debt on his watch.

The coming spending fights make the Christmastime tax increase battle seem like child’s play. While everyone knew the tax drama would end with the rich paying more taxes, no one can telegraph how the coming spending fights will unfold. And the economic stakes are more dire.

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“For too long, the pitch was, we’ll deal with it next time,” said Rep. Jason Chaffetz, a conservative from Utah. He said GOP lawmakers are prepared to shut things down or even default if Obama doesn’t bend on spending. “No one wants to default, but we are not going to continue to give the president a limitless credit card.”

Starting Monday, Boehner will huddle with his leadership team to discuss his preliminary thinking on a spending strategy. A source who attended meetings to prepare for those private talks said GOP leaders are authentically at a loss on how to control members who don’t respond to the normal incentives of wanting to help party leaders or of avoiding situations — like default — that could be public relations nightmares.