Two weeks before Election Day and it's still hard to pinpoint "the moment."
Modern presidential politics have often been defined by turning points in a campaign, typically when one candidate does or says something stupid. Or, if not stupid, at least something that reminds many voters of the misgivings they already harbor about the candidate.
The examples have become legend.
Michael Dukakis, attempting to show he wasn't soft on defense in 1988, rode in a tank for a PR event - and looked like Rocky the Flying Squirrel. He would get trounced two months later.
President George H.W. Bush reportedly marveled at a grocery price scanner in 1992 - technology that had been around for years at that point. The anecdote fed concerns he was out of touch about economic problems facing the middle class, ultimately costing him a second term.
Al Gore repeatedly promised in 2000 to put Social Security in a "lock box," an awkward phrase that became lampooned on the comedy programs and bolstered perceptions that he was too stiff to lead.
And John Kerry wind-surfed off the coast of Nantucket after the Republican National Convention, perhaps hoping to show that he was virile and unconcerned about the opposition. It only enlarged the elitist image he was hoping to allay.
Leading up to the current campaign, it was widely thought that the Internet would capture and amplify such game-changing moments like never before. Certainly one of the two candidates couldn't possibly survive being YouTubed, blogged about, twittered and flickred in the news cycle that never sleeps.
But the virtual Venus Flytrap doesn't seem to have ensnared Republican John McCain, who is trailing in the polls, or Democrat Barack Obama.
Both the senators, of course, have had numerous ups and downs in a campaign that has extended for more than a year. And the turning point of a race often isn't evident while it's occurring. Sometimes, it's not fully appreciated until after the outcome is known.
But the defining moments of this campaign, judging from hits online, have been about others as much as the two men running for president: Obama Girl, Joe the plumber, the Rev. Jeremiah Wright, Katie Couric, Tina Fey as Sarah Palin, Sarah Palin as Sarah Palin.
If McCain does lose, his reference to Obama as "That One" during the second presidential debate might be remembered as a turning point. It was more odd than self-destructing. But like many fulcrum moments in campaigns past, it might have given shape to an existing concern among voters on the fence - in this case, that McCain can be surly and tempestuous.
Within days, online retailers offered Obama supporters T-shirts with captions such as "This One is Voting for That One," and "It's President That One to you." The debate exchange has been replayed on YouTube a hundred thousand times (although that pales next to the millions of replays for Fey's entrancing Palin impressions on Saturday Night Live, which have been watched days and weeks later online by more people than watched the live versions).
Perhaps Obama and McCain haven't been tripped up by some misspeak or embarrassing image because they're especially savvy or possibly their fear of platforms like YouTube was so great their handlers have had much greater caution about photo ops that can go oh-so wrong.
Or it could be that McCain's choice of Palin - his biggest misstep, according to commentators on both the left and the right - has sopped up so much attention of the media and pop culture world, there's been less time and focus spent on otherwise innocuous pebbles along the campaign trail that sometimes have grown into boulders.