The word "snafu" originated as a US military acronym in World War II standing for "situation normal: all fouled (or f*****) up". According to the Oxford English Dictionary (OED), it was originally "an expression conveying the common soldier's laconic acceptance of the disorder of war and the ineptitude of his superiors".

Desperate times call for desperate neologisms. In 1944, United States bomber crews came up with another acronym to describe a state of affairs more extreme than snafu: "fubar", which stands for "f***** up beyond all recognition". The OED defines fubar as "bungled, ruined, messed up. Also: extremely intoxicated".

Snafu is the rifleman's word of choice, meaning that it's the usual, same old effed-up mess. Fubar, by contrast, is the pilot's term, appropriate to a catastrophic crash-landing or the aftermath of a wild booze-up in the officers' mess.

The big question we in America confront, as election day slouches towards us, is whether the future of the US will be snafu or fubar. Slumped in the Democratic corner, her haggard visage being fanned by anxious trainers, is Mrs Hillary Clinton, candidate of the effed-up status quo. Impatiently bouncing off the ropes on the other side of the ring is the overweight, orange-featured personification of very, very risky change.

As I write, the future still seems more likely to be snafu. But the effed-up status quo's margin of advantage suddenly looks much smaller than anyone had thought in the dog days of summer.

The conventional wisdom, as last month drew to a close, was that Mr Donald Trump's campaign was in free fall. Some Clinton supporters had even begun to predict a landslide, as in 1964 when Mr Lyndon Johnson crushed Mr Barry Goldwater by 61 per cent to 38 per cent, winning all but six states.

What a difference a couple of working weeks have made. In the 14 most recent national polls, Mrs Clinton is ahead in only seven and by margins of between 1 and 5 percentage points. The latest Los Angeles Times poll has Mr Trump ahead by nearly 6 points. Even the closely watched CBS News/New York Times poll of likely voters has the race tied, taking into account the substantial numbers of votes likely to go to the Libertarian and Green candidates. Moreover, Mr Trump is now ahead in the two most important battleground states - Ohio and Florida.

What has changed? The easy answer is that Mrs Clinton has just had her worst week of the campaign. It began when she dismissed "half" of Mr Trump's supporters as belonging in "the basket of deplorables... racist, sexist, homophobic, xenophobic, Islamophobic - you name it".

It continued when she lost her balance at an event to commemorate the 15th anniversary of the Sept 11 attacks, forcing her campaign to admit she is suffering from pneumonia, a fact she had evidently hoped to conceal. Yet, there is something more profound going on here.

Last week, Mrs Clinton's supporters seized on new data from the Census Bureau, showing median household income rose by over 5 per cent in real terms last year. Poverty is down. So is the number of Americans without health insurance. So is unemployment.

Moreover, despite the low regard in which the government is generally held, there is new evidence that public programmes significantly mitigated the impact of the great recession. Pre-tax, according to a new McKinsey Global Institute study, 81 per cent of US households were worse or no better off in 2014 than they were in 2005. But after redistributive government programmes (taxes on the rich, benefits to the poor), that share was fewer than 2 per cent of households.

All this seems grist to the mill of a campaign that essentially promises continuity. Yet there is a problem.

Take another look at those figures for inflation-adjusted median household income. Yes, it was US$56,516 (S$77,100) last year, up from US$53,718 the year before. But back in 1999, it was US$57,909. In other words, it's been a round trip - a bumpy one indeed - since Mrs Clinton's husband was in the White House.

Two-fifths of Americans surveyed last year by McKinsey say their financial position is worse than it was five years ago and/or agree with the statement: "My financial position is worse than my parents' when they were my age." Nearly half of this group do not expect their situation to improve, and a third expect their children to advance more slowly than their own generation.

Telling Americans they are nearly back to where they were 17 years ago and expecting them to be grateful, therefore, looks like a losing strategy. When two-thirds of the population - and an even bigger proportion of older white voters - say the country is on the wrong track, they are not (as Democrats claim) in denial about the Obama administration's achievements. They are saying that the country is on a circular track and has been since this century began.

To see why Mr Trump is gaining on Mrs Clinton despite his numerous flaws as a candidate, compare their economic policy proposals. With Mrs Clinton, you get more of the same: more spending - approximately US$1.5 trillion over the next decade, a large proportion of it on infrastructure - paid for by higher taxes on richer households, plus more regulation, especially of banks and pharmaceutical companies. Call it Obama Plus: the trains go round in circles, the government keeps on growing but the economy, as a whole, limps along at 2 per cent a year.

In contrast, Mr Trump offers acceleration along a new track, albeit at the risk of derailment. This is true even when he is on his best behaviour, as he was on Thursday at the Economic Club of New York.

Much of this speech was red meat for the Republican establishment that he needs to keep on board: tax simplification and tax cuts, increased spending on defence and border security, and deep cuts in environmental and consumer- protection regulation.

Ironically, the Keynesian economists who support Mrs Clinton are on the wrong side, because even the Trump campaign admits his tax cuts would cost US$4.4 trillion over the decade. He, not Mrs Clinton, is the true candidate of stimulus, as his budgets would come close to balancing only if growth went up to 3.5 per cent a year.

On top of all that are Mr Trump's earlier pledges to restrict immigration, free trade and offshoring - pledges (as the McKinsey study also showed) that are especially appealing to those Americans who feel most pessimistic about the future.

Neither the snafu candidate nor the fubar candidate is trusted by much more than a third of voters. Mr Trump is clearly the riskier candidate. Fewer than a third of voters regard him as a safe choice, compared with close to half who have that view of Mrs Clinton.

On the economy and jobs, however, he leads her by 51 per cent to 43 per cent. And when it comes to bringing about "real change in Washington", Mr Trump leads by 48 per cent to 36 per cent.

The prediction markets and the political pundits still have Mrs Clinton as the favourite. But wouldn't you risk being fubar... if it was your only shot at avoiding four more years of snafu?

THE SUNDAY TIMES, LONDON

•The writer is a Hoover Institution, Stanford University senior fellow.