Crisis mode is becoming the new normal for Congress, which in the past nine months has stonewalled its way into three government shutdown scares and an unprecedented near-default on the national debt.

Almost gone on Capitol Hill is the old way of resolving disputes: backroom deals greased with federal dollars destined for lawmakers' home districts. In its place is a new brinkmanship fixed almost exclusively on cutting federal spending.

The new modus operandi? Draw a line in the sand, threaten Armageddon, then hold out until the other side caves or financial markets tumble, whichever comes first. It's an approach, say critics, that calls into question Congress's capacity to fulfill its basic constitutional obligations.

"It's governing by threat, high stakes, and cliffhangers," says Julian Zelizer, a congressional historian at Princeton University. "You wait until the last minute; both sides are willing to threaten shutdown. The worst scenario is that the players are getting used to governing this way. The more you do something like this, the more comfortable you get to do it again."

The new brinkmanship coincides with the Republican takeover of the House in January, including 87 freshmen, many elected with tea party support. The new majority had campaigned to cinch government, get the United States on a sustainable fiscal course, and not raise taxes, period. The intensity of that commitment – and the willingness of GOP leaders to stick to it, even in the face of possibly draconian outcomes – stunned the Obama White House and congressional Democrats, who took months to adapt.

With this brand of power politics, Republicans have managed to dictate the conversation in Washington – effectively shifting it from the need for economic stimulus to the need to cut, cut, cut. Factors that might have intervened to prevent walking up to the brink – namely personal ties across the aisle – have faded. And, of course, soaring US deficits do lend their own sense of urgency.

So far, the US balance sheet looks marginally better after these showdowns. But Congress's reputation as an institution capable of governing has taken a battering.

Such a culture shift has happened before, but on the Senate side. It used to be that filibusters were relatively rare events, but over the past 25 years they have been threatened often – so much so that a 60-vote "supermajority" is now needed to move any remotely controversial measure.

Here's how a routine issue – wrapping up the previous Congress's unfinished business – became a dance on the cliff.

Funding for the second half of fiscal year 2011 (April-September) became the test case of the new GOP majority's clout. A new Congress typically deals with unfinished spending bills of the previous Congress by criticizing the outgoing majority for incompetence, then passing a monster bill with enough new spending for home districts to ensure it passes. But this time was different: House Republicans last fall had campaigned to cut $100 billion from President Obama's budget request.

After a battle among House GOP conservatives, Republicans on April 7 agreed to a lesser $38.5 billion cut. Speaker John Boehner persuaded caucus members that they had won a point of principle and would only lose public support if it came to a shutdown, just as they had after standoffs with President Bill Clinton in 1995.

But a subsequent analysis by the Congressional Budget Office found that the budget deal would whittle spending by only $352 million. Critics, blaming Mr. Boehner, dubbed the outcome "smoke and mirrors." House leaders reassured angry conservatives that this was merely a first step toward changing the culture of Washington. The point of maximum leverage was yet to come: Mr. Obama's request to raise the US debt limit.

Congress usually deals with raising the national debt limit by criticizing the president and then passing a bill with as little fanfare as possible. It would be inconceivable for any Congress to jeopardize the full faith and credit of the US, said officials from both Republican and Democratic administrations.

In fact, Congress had raised the national debt ceiling 78 times since 1960, 49 times at the request of Republican presidents and 30 at the behest of Democrats.