Raising the debt ceiling, which would give the Treasury Department permission to borrow more money, has been approved by Congress as a matter of course through recent history, as the United States has routinely spent more money than it takes in taxes and fees.

What has changed this time?

“Last year’s election is the answer to that question,” said James Riddlesperger, chairman of the political science department at Texas Christian University.

The Republican party retook control of the House of Representatives last November with a wave of 87 new members backed by the low-tax, small-government tea party wing of the party.

Also, that freshman class and many Republican holdovers have signed a pledge to their constituents that they will not vote to raise taxes for any reason.

There’s the rub.

President Barack Obama agrees with conservative Republicans that there must be deep cuts in government spending to curb the growing American deficit and debt. He disagrees, however, on how and what to cut and, most fundamentally, on their refusal to allow any increase in taxes, particularly for the wealthiest Americans.

So far, through a long and tortured negotiating process, neither Republicans nor Democrats have exposed a formula for compromise that is essential to preventing a US default. The Treasury hits on 2 August the current $14.3 trillion cap on US borrowing.

Credit rating organisations are threatening to downgrade US debt if the ceiling is not raised, and Obama and most economists predict that interest rates would spike on mortgages, consumer loans and credit cards. The government would be faced with the choice of paying its bond holders or issuing cheques to tens of millions of Americans who rely on Social Security pension payments from Washington.

It is widely feared that a default would push the US economy back into recession or worse and set off chaos in the global economy.

Most Americans appear to be in favour of a middle ground, and that puzzles Natalie Davis, professor of political science at Birmingham-Southern College.

“The disconnect between refusing to raise tax revenues period, and what we’re seeing in the polling is very hard to explain,” she said.

For example, a CNN/ORC International poll released on Thursday found that 64% favoured solving the US debt problem through a combination of spending cuts and tax increases on higher-income Americans and some businesses. That is broadly the Obama and Democratic position.

So how can the conservative Republicans stand firm?

“Our historic American pragmatism for solving problems has given way to staying in power,” said Davis.

While national opinion polls show a big majority of Americans do not agree with the 87 new House Republicans on raising taxes, those members don’t care. They represent just 20% of 435 total House districts. What counts for them is what the people who elected them will do when they go back into the polling booth in 2012.” Members of the House stand for re-election every two years.

“The public wants their side to win, and the members of Congress are in a real bind. Come the election their constituents who put them in office to cut spending and block new taxes will ask: ‘Did you do your job?’ That’s now defined as did you win on those issues,” said Jack Holmes, professor of political science at Hope College.

Jim Broussard, professor of history at Lebanon Valley College, thinks the brinkmanship on both sides is all about the 2012 election.

“If I were Obama, I’d drag this out right to the deadline knowing in the end I would make a deal the Republicans would accept. And it’s the same for the other side,” he said.

He predicted a final solution would surface that raises the debt ceiling by an amount that would last through the 2012 election. In return there would be significant spending cuts and revocation of tax loopholes that benefit the wealthy and big business.

That is about where the two sides were weeks ago, and it is a compromise that would play well with moderate and independent voters. It also would not do too much damage with the political base of either Obama or tea party Republicans in Congress.

The explanation: “We could not let the country default.”

House Speaker John Boehner, a Republican, already was headed in that direction on Thursday.

“At the end of the day,” he said, “we have a responsibility to act.”

Steven R. Hurst is AP international political writer