It’s a serious question. On the basis of fundamentals, the race should be a squeaker. The Yale economist Ray Fair’s prediction model, which ignores the opinion polls and just looks at economic factors, currently puts Obama’s share of the popular vote at 49.5 per cent, implying that Romney would almost certainly get a narrow majority in the electoral college and win the election. Because the margin of error in Fair’s forecasting equation is three per cent, he isn’t really predicting a Romney victory; he’s just saying that the race should be close, really close. As of today, it isn’t.

According to the Real Clear Politics poll-of-polls, which averages out all the most recent surveys, Obama is leading by more than three points. Since the start of the year, Romney hasn’t led the poll-of-polls. He has only drawn level once—immediately after the Republican convention. And in many of the swing states, such as Ohio and Virginia, the survey data looks even worse for him. He could still come back, of course, but at this stage it will take something dramatic to change the dynamics: a foreign-policy disaster, a terrible piece of economic news, a big slipup by Obama in the debates.

What’s gone wrong for Romney? Here are seven possible explanations:

1. The Romney campaign is incompetent. In a column a couple of days ago, Peggy Noonan, the former White House speech writer for Ronald Reagan, said publicly what many Republicans have been saying in private for months: “It’s time to admit the Romney campaign is an incompetent one. It’s not big, it’s not brave, it’s not thoughtfully tackling great issues. It’s always been too small for the moment.” Stuart Stevens, Romney’s mercurial campaign manager, is the piñata of the moment, with Republicans blaming him for everything from failing to settle on a clear message, hogging too much responsibility inside Team Romney—he’s in charge of speech-writing and advertising, as well as overall strategy—and bungling Romney’s speech at the convention. Stevens “sold himself as a kind of mad genius,” Noonan noted acidly. “I get the mad part.”

2. Romney is incompetent. No big-name Republican has come right out and said this, but many are increasingly convinced of it, especially following the emergence of the “forty-seven per cent” video. Bill Kristol, the editor of the Weekly Standard, called Romney’s comments on the video “stupid and arrogant.” In a column in Thursday’s Wall Street Journal, Karl Rove, who has been one of Romney’s biggest supporters, noted, “There’s little tolerance among Republican donors, activists and talking heads for more statements by Mr. Romney that the media can depict as gaffes.” It seems that almost every week lately Romney has had to walk back, or clarify, something embarrassing he’s said.

3. It’s all the G.O.P.’s fault. A month ago, on the eve of the Republican convention, I wrote a post saying that Romney’s main handicap wasn’t his campaign manager or his tendency to trip himself up but the fact that he was running as the representative of such an extremist and unpopular party. “It’s a protest movement rather than a party of government,” I wrote. “Even in the most favorable circumstances, it’s barely electable at the national level.” That still seems right. Even after his problems, Romney’s approval ratings (low forties) are running about ten points ahead of the G.O.P.’s ratings (low thirties).

4. Americans like Obama, or the idea of Obama. The high hopes of 2008 faded long ago, but outside of right-wing talk radio and other diehard Republican circles, there isn’t much overt animosity toward the President. To the contrary, most people seem to respect his calm approach and his repeated offers to work with the Republicans even though they have turned away all his overtures. Romney has tried to counter Obama’s personal popularity by arguing that he’s a nice guy who isn’t up to the job of President. So far, this argument doesn’t seem to be resonating with moderates and independents.

5. It’s the economy, stupid. Yes, the jobs picture is pretty dismal. But the unemployment rate, at 8.1 per cent, is a full percentage point below what it was at this time last year, and other economic indicators are looking up. A year ago, on September 20, 2011, the Dow closed at 11,408.66. On Thursday, the market closed at 13,596.93. In twelve months, it has risen by nearly twenty per cent. House prices, which have been depressed for years, are also picking up in many areas, as are housing starts. In Thursday’s Wall Street Journal, Michelle Meyer, an economist at Bank of America Merrill Lynch, said: “The housing recovery has indeed started.” For the one-in-four working-age Americans who are still out of work or working part-time because they can’t find full-time employment, the Great Recession is still very real. But for people in a job, many of who own their own home and have a 401K, the financial outlook has improved substantially over the past twelve months.

6. It’s all demographics. At the end of last year, Ruy Teixeira—the Washington-based political scientist who has long argued that the rising number of Hispanics, working women, highly-educated yuppies, and other Democratic-leaning groups in the electorate would deliver a stable governing majority to the Democrats—characterized the 2012 election as “Demographics versus Economics.” As of now, demographics may be winning out. On the national level, most opinion polls show a double-digit gender gap in Obama’s favor. Meanwhile, in formerly Republican states like Colorado, Nevada, and Virginia, the Hispanic share of the vote is rising rapidly, and Obama is running ahead despite heavy spending by G.O.P.-leaning groups.

7. Things aren’t really so bad. The contrarian case for Romney is that, despite all his goofs, he’s still doing fairly well in the national tracking polls—in Thursday’s Gallup update, the two candidates were dead level at forty-seven per cent—and he’s still got time to turn around the swing states. Karl Rove, while acknowledging Romney’s recent missteps, argued in his column that at this point in the 1980 campaign Ronald Reagan was trailing Jimmy Carter in some national polls. Referring to this week’s brouhaha over the fund-raiser video, Rove called it “a classic example of the commentariat investing moments with more meaning than they deserve.”

This one doesn’t withstand scrutiny: Romney’s campaign is in a world of trouble. Rove heads the biggest G.O.P. Super PAC, American Crossroads, and he played a significant role in persuading the Party to accept Romney as its candidate. He has a strong interest in talking up his prospects. And even he conceded that Romney “must reassure voters he’s up to the job of being president.”

The other explanations all have merit—and aren’t mutually exclusive. In any election, fundamental factors, such as demographics and the economy, are important. As Teixeira explained in a lengthy interview I did with him back in June, the country is changing so fast that Obama can afford to lose among white men by up to twenty percentage points and still garner enough votes to win. The lacklustre economy is still the biggest thing working in Romney’s favor, but rising stock prices and the nascent recovery in the housing market appear to be having an ameliorating effect.