As the dust begins to settle on what just about everyone agrees was a weak performance by Barack Obama in his debate with Mitt Romney on Tuesday night, it's interesting to think about what the most damaging moments have been to both candidates in the campaign so far, and through which media they occurred.

Obama's worst moment, clearly, was his lackluster performance in the debate.  Nonverbally, he looked tired and uninterested.  Verbally, he failed to engage Romney for most of the debate.  In this traditional mass media event on television - seen by 60 million people - Obama was clearly at a loss.

Romney's worst moment, clearly, was the grainy video recording of his 47% remark that was put up on YouTube and further disseminated on cable and network television.   Unlike the debate, the recording and initial postings of this video were not seen by millions of people.  Like all social media - or, what I call "new new media" - the impact of this viral video grew exponentially over a period of time.

The 47% remark cost Romney in the polls.  It's too soon to know what Obama's poor debate will cost him in the polls.  But it's unlikely that a debate seen by 60 million will not have some negative impact.

So we're left, at this point, with a contest not only between Obama and Romney, but between social and mass media.  Social media have thus far helped Obama and hurt Romney.  Mass media, at least insofar as Tuesday's debate and its single broadcast to millions of people, have had the reverse result.

It has been tempting to count the role of mass media out, or at least demote its importance, in our age of social media such as YouTube and Twitter.   But as Isaac Asimov explored dramatically in his Foundation trilogy decades ago, a declining empire (read: mass media of today) can still exert powerful influence in a new age (read: social media).

Media and communications are, of course, by no means the only factors that determine an election.  Further, Obama may well do much better in the next debate.  But  if the current split continues - Romney hurt by social media, Obama by mass media - the election would well be decided by which media have the most power in our world today.

See also On Last Night's Obama Disappointment and Romney's 47% Remark and the Power of New New Media