How did we get here? It’s a salient question as millions of Americans cautiously prepare for the likely shutdown of their federal government this afternoon (Australian time).

The answer, though, is patently obvious. This ludicrous scenario, in which politicians and lawmakers have manufactured a crisis that will negatively impact millions of its constituents and further sour public confidence in elected officials, has played out in a dismally predictable manner.

The lack of civility — much less a willingness to negotiate — only makes it all the more discouraging for a weary and wary American public.

The chief reason for the angst is a determination by the Republican Party that the key plank of Barack Obama’s presidency, his Affordable Care Act, should fail. The act, which Republicans derisively (but effectively) re-branded as “Obamacare”, is a key legislative achievement of the President. It aims to reduce the number of uninsured Americans and reduce healthcare costs. Republicans though, have determinedly dug their heels in.

This is despite the fact, as Obama irritably points out, the act has been law for three-and-a-half years, has passed both houses of Congress and had the Supreme Court rule it constitutional. Not to mention Obama handily defeated Mitt Romney in last year’s presidential election — an opponent who sought to repeal the law.

This act will likely improve the quality of life for many Americans, and the fact that the public has not completely turned on the Republicans speaks to the sizeable shortcomings in both Obama’s explanation and implementation of the policy.

It has been a clumsy sell from the Democrats, who control the Senate along with the White House. The Republicans control the second house of US Congress, the House of Representatives. The inability for both houses to pass policy and legislation denotes the inability of Congress to pass a conventional budget.

We’ve been here before, you will recall. A temporary spending measure was implemented six months ago to keep the government from shutting down in March. It expires at midnight in DC (2pm AEST).

Earlier today, the Senate rejected a Republican proposal from the House that would vote for new spending predicated on Obamacare being delayed or its funding gutted. Republicans are adamant they will not back down. Failing a last minute miracle, a shutdown is highly probable. The President appeared incredulous today following the stalemate:

“The idea of putting the American people’s hard-earned progress at risk is the height of irresponsibility and doesn’t have to happen. Let me repeat that: it does not have to happen. All of this is entirely preventable … One faction of one party in one house of Congress in one branch of government doesn’t get to shut down the entire government just to re-fight the results of an election.”

Who will pay the highest price for this fiasco? Confusion reigns among the public. Several states have road-blocked Obamacare’s implementation. Tellingly, polls suggest that many of those to whom the policy would most directly benefit are either against it or hold significant reservations around it.

“A giant fear, telegraphed today by the financial markets around the world, is that a government shutdown of any length of time could impact Congress’ ability to raise the US debt ceiling.”

If the shutdown goes ahead, almost 1 million government workers will be either involuntarily furloughed (sent home from work indefinitely without pay) or not paid if they do work. Ninety-seven per cent of NASA’s 18,000 employees will be told to stay home without pay. So will 94% of the Environmental Protection Agency’s staff and 80% of Treasury. All national parks and monuments will close. Visas and passports will not be processed.

Mail delivery will continue though, as will medical care, airport security, border protection and other activities deemed “essential”. Many government department heads spent the weekend determining just what that means.

The previous federal government shutdown began in 1995. Media coverage from the time is an unusual time capsule. The garrulous then-president Bill Clinton and House leader Newt Gingrich eventually sat down and hammered out a solution. Gingrich was slaughtered by the press and Clinton won re-election soon after. The media environment today has significantly changed.

It’s a far cry from the taciturn Obama and current Republican leaders, who themselves must negotiate with the likes of eccentric, loquacious and often ego-maniacal Tea Party senators like Ted Cruz. The 42-year-old Texan embodies the dogmatic tone of the Republicans. Elected from the GOP’s libertarian wing, he and compadres Marco Rubio and Rand Paul have ensured Republicans are now beholden to extremist elements within their own party. Moderate voices are drowned out, particularly those facing primary fights next year against far-right candidates.

A giant fear, telegraphed today by the financial markets around the world, is that a government shutdown of any length of time could impact Congress’ ability to raise the US debt ceiling.

If there is no agreement to raise the borrowing limit by October 17, the US government could default on its outstanding borrowing and would be unable to issue any bonds. A fundamental assumption in world financial markets, that the US will always pay its bills, would be shattered. It’s an uncomfortable prospect for world financial markets.

Yet the real debate should be about the spiraling costs of medical care in the US and the profits gleaned off those unlucky enough to fall ill or suffer a medical emergency. Washington lobbyists will ensure that does not occur, however.

Meanwhile, not coincidentally, Obama’s new health insurance roll-out is due to begin tomorrow. His team announced a cluster of new health insurance options for Americans earlier today, designed to increase online alternatives and coverage for consumers here. Shutdown or not, it starts tomorrow.

For their part, Republicans say that even more concessions relating to their economic and social policy agenda like, say, pushing through the Keystone Pipeline, will be required before they agree to lift the debt ceiling again.

Today was a grim portent to what may be ahead later this month: an ugly dispute that could wreck havoc on world markets and destroy the federal government credit rating. It’s a depressing, although increasingly likely scenario.