The news that President Barack Obama's acceptance speech at the Democratic National Convention was the "biggest political moment ever" on Twitter isn’t exactly surprising, but it’s worth taking a look at how social media influences political contests.

It’s no secret that Democrats have a stranglehold on the youth vote — voters aged 18-29 picked Obama over McCain in 2008 by a 3-1 margin. And it’s thus no coincidence that the Democratic Party has, of late, pursued an aggressive social media campaign.

If the respective Parties’ social media footprint foreshadowed the general election, Obama would win in a landslide. According to a Reuters piece, the incumbent’s speech on Thursday inspired 52,756 tweets per minute after it ended.

"The peak tweets per minute, following some of Obama's most memorable lines, exceeded all other moments for any speaker during either the Democratic or Republican conventions," said Reuters’ Nichola Groom.

And it’s worth noting that the 4 million tweets generated from the DNC’s final day are close to the total number of tweets for the entire Republican National Convention.

Left unsaid is whether those 4 million tweets were supportive or disparaging of Obama and the Democrats. Obama could’ve energized his base or inflamed the opposition. It’s also unclear who consumed those tweets and how receptive they were to the tweeter’s message – were those 4 million tweeting to the converted, or did the 140-character-or-less treatises reach a wider, mixed audience?

It’s difficult to quantify these questions, but we can look at the 2008 general election to provide some clarity. The Obama campaign deployed a vast social media campaign, and it paid dividends. Obama’s 844,927 MySpace friends dwarfed McCain's 219,404, while Obama gained 10,000 followers over election day vs. McCain’s 964.

The Twitter divide was even more vast.

According to ReadWriteWeb, “Obama gained 2865 new followers between the 3rd and 4th (for a total of 118,107), while John McCain's Twitter account only has a paltry 4942 followers in total.”

For the record, the current social media breakdown is as follows:

Obama has 19,572,843 Twitter followers vs. Romney’s 1,080,607, Obama has 28,472,015 Facebook “Likes” vs. Romney’s 6,650,020, and while Obama has a robust 1,716,366 MySpace followers, I couldn’t find an official page for Romney (though it is possible I may have missed it).

Why such a wide disparity? The simple answer is that young people have acclimated more readily to social media, and the youth vote goes solidly Democrat; in the ’08 elections, Obama grabbed the 18-29 demographic by 66-32% — by far, the widest gulf among any age bracket.

ReadWriteWeb astutely points out that "The demographics of social media users tend to fall in line more closely with those of today's Democratic voters."

So it’s possible that social media campaigns — which tend to find more receptive ears among youth voters — are merely preaching to the converted.

But considering that young people, as a demographic, have the lowest percentage of registered voters, it’s significant that social media efforts excite them and compel them to vote.

In 2008, a mere 58.5% of citizens aged 18-24 were registered to vote, 66.4% of 25-34 year-olds were registered, and on up.

While Obama’s social media footprint is indisputably greater than Romney’s, the implications of this are unclear. It’s possible that the majority of Republican voters — or a healthy percentage of them — aren’t active on Twitter. It’s also possible that there’s a certain overlap between the two candidates’ social media followers — well-informed voters may wish to follow the opposition.

This overlap, however, is likely minimal.

But even if social media efforts are preaching to the converted, the real aim is to increase voter turnout among a demographic already inclined to vote Democrat. This is why the Obama campaign has zeroed in on social media. If Republicans want to derive these same benefits, they wouldn’t get there by simply ramping up their social media efforts. The answer lies deeper (and beyond the scope of this publication).

What do you think? What role — if any — will social media play in the 2012 presidential election?