I’m reading one comment over and over again in response to criticism here and elsewhere about Barack Obama’s speech — that those who criticize it weren’t the audience for it anyway.  I admit that I’m a Republican who has no intention of voting for Barack Obama.  However, shouldn’t that have been the audience for this speech?

Presidential candidates rarely win office by only holding their own partisans.  That happened in 1992 and to a lesser extent in 1996 because of strong third-party bids by Ross Perot, but otherwise presidential elections become almost entirely binary affairs.  One can help tip the scales by energizing the base, but presidential elections are won by convincing skeptics, not just by pandering to the faithful.

When Obama (and John McCain) hit the campaign trail, they know that the audience comprises the faithful.  When they have the opportunity to go live on every network, though, the candidates have a much wider audience — and a much larger opportunity to convince the skeptics, and even impress their opponents.  Conventions provide the greatest chance in the race for bringing this kind of audience to a candidate.

So why just focus on the faithful, instead of convincing the skeptics that Obama is more than just talk?  Either Obama simply isn’t adept enough to understand the difference between a campaign event and a nationally-broadcast event — and I don’t believe that — or he’s still worried that his base has fractured too badly for him to win.  After a summer of policy reversals and hedging on still more, Obama can’t afford to reach out in any substantive way beyond the limits of his base.

And again, if we needed more proof of that, we could simply have watched the tone and tenor of the convention itself.  Its harsh, complaining, and Bush-obsessed speeches were calculated to present an enemy around which this fractured base could rally, rather than make the sale with the general public.

Obama is a brilliant orator, and his delivery last night was very good.  However, it wasn’t good enough to get beyond the limits of his base, and that’s what made this week a lost opportunity for Obama and the Democrats.