What's welling up in America's ruling Democrats is not yet a full-throated scream of desperation.

But as Samuel Johnson famously remarked, the prospect of being hanged in a fortnight concentrates the mind wonderfully.

For the most part, Barack Obama's supporters are still clutching the cloak, woven of equal parts optimism and moral certainty, that they wrapped around themselves four short years ago.

But the fear that their world is falling apart has begun to take hold. As it should.

Four Novembers ago, they were marching, led by the first biracial president-elect, a man who would, by his very appearance and preternaturally calming nature, restore the world's faith in America and end the hateful, paralyzing polarity into which this country had descended.

I was in Chicago's Grant Park to watch him accept the nation's resounding verdict last election night. I count it among those rare moments of history that reporters occasionally get to witness.

Barack Obama fairly glowed with an aura of triumph and generational change, and soon after would promise to preside over a great "healing."

How, then, did he arrive at the place from which he debated Monday night in the third and last of this election's televised debates?

Resorting to rehearsed zingers and smallish attacks, as the rather awkward fellow who couldn't even capture the Republican nomination four years ago sat, taciturn, across the desk, politely deflecting him?

How to explain the undertone of desperation (go back and listen closely, it's there) from a man who was, just a month ago, the personification of cool, brainy confidence?

The Romney advance

More particularly, how to explain the relentless polls? Romney leading nationwide, according to at least a few respectable surveys, Gallup among them; and closing the gap in those crucial swing states?

At this point, Romney appears to be doing so well in Florida, where the 2000 election was decided, that there is actually speculation about Obama abandoning that huge prize and concentrating on the Midwest.

Obama and Romney, following the presidential debate in Boca Raton, Fla., on Monday. Who's hopeful now? (Reuters)

Democrat spinners are scoffing at that notion, and call the so-called tracking polls, like the one by Gallup that currently has Romney ahead nationally by five points, "outliers." As they may well be.

They are also clinging to analysis like Nate Silver's remarkable "FiveThirtyEight" polling blog at the New York Times, which continues to argue that Obama remains in the better position to win the White House — that even if he loses the popular vote, the regionally weighted mathematics of the Electoral College will still push him over the top.

That possibility may well be, too, although it would reek of irony, given the four years of constant whining from Democrats about George W. Bush having lost the popular vote while winning the White House in 2000.

Still, what counts in polls is the trend line. And when all the polls are averaged out, as they are on the Real Clear Politics website, it's clear that Mitt Romney has relentlessly advanced in the past two weeks.

Today's standings were 47.9 – 47.2 in favour of Romney, when the nine most recent national polls were averaged together.

Moderate Mitt

It is also clear that Barack Obama has only himself to blame for this state of affairs.

Just three weeks ago, he not only led Romney by a few points in the popular vote, he had a consistent lead in the majority of swing states. Furthermore, as the president, he possesses the potent tool of incumbency.

So what happened?

Well, first, he turned in that soporific performance during the Oct. 3 debate that is already going down in U.S. political history.

Then Barack Obama let Mitt Romney happen.

This rich patrician, despised by many within his own party for his vacillating, who seems painfully unable to connect with average wage-earners, has acquired the ability to look and sound both reasonable and presidential.

Suddenly, the man who, back in February, was describing himself as a "severe conservative," and whose advisers include some of the same neoconservatives who pushed America into a wrongheaded war in Iraq (which Romney himself supported) is now respectfully quoting "Arab scholars" to Barack Obama.

Foreign aid, education, help in building "civil societies" and pushing for gender equality. That's how the new, moderate Romney would defeat al-Qaeda.

Should America "divorce Pakistan," he was asked Monday, and cut off the billions of dollars in aid it sends that rather dubious ally, as many Republicans have suggested?

No, said moderate Mitt, the answer is diplomacy. "We're going to have to work with the people in Pakistan to help them move to a more responsible course."

And by the way, Mr. President, my respectful congratulations for killing Osama bin Laden.

Who's hopeful now?

Would Romney have stuck with Egypt's Hosni Mubarak as the dictatorial old American ally struggled to hang onto power in his final days, as Republicans have said Obama should have done rather than open a path for the Muslim Brotherhood to take power?

No, supporting the people was the right course, Romney said. He only wished America had better foreseen the pitfalls ahead, but that's water under the bridge.

Invited by the moderator, CBS's Bob Schieffer, to drive home the relentless Republican attack on how the administration reacted to the killing of the U.S. ambassador and three others in Benghazi, Libya, in September, Romney declined, preferring to talk about helping the Libyan people.

"We can't kill our way out of this mess," he said at one point. You could almost hear Obama saying the same sort of thing, four years back.

Monday night, though, Obama attacked first and attacked often, effectively calling Romney a liar, pointing, sometimes correctly, to his contradictory declarations, and tossing out sarcastic slap downs.

But it just didn't seem to work. Once more, Romney was a step ahead.

Rather than firing back, he responded with an air of regretful forbearance, on two occasions telling Obama "attacking me is not an agenda. Attacking me is not talking about how we're going to deal with … challenges."

Then, in his closing statement, he talked about the torch changing hands. He talked about getting people off food stamps, "not by cutting the program, but by getting them good jobs."

He talked about reaching across the aisle in Congress, and working with "good Democrats and good Republicans to do that." And he talked about hope.

Sound familiar?

As the conservative pundit and former Bush-era speechwriter, Peggy Noonan, said on Sunday, the most interesting thing about this race now is that no one has any idea how it's going to turn out.

But if Obama can't stop Romney's momentum, I may well be witnessing another historic moment in Chicago two weeks from now.

And listening to a long, loud, anguished progressive scream.