On the Republican side, a website known as 140 Town Hall plans to conduct a Twitter debate on July 20 among GOP presidential candidates, and has announced that Michele Bachmann and Herman Cain have agreed to participate.

Anything that serves to curb politicians’ natural tendency toward long-windedness is welcome, but a Twitter debate risks turning complex issues into a parlor game.

Candidates of both parties are increasingly drawn to social media because of recent history that confirms their impact. Democrat Howard Dean’s 2004 presidential bid is often cited as providing the first Internet breakthrough, creating what has come to be known as a Netroots campaign. Dean used the Internet to distribute commentary, track voters, and, most significantly, to raise money.

By 2008, Obama and John McCain each had large digital campaign operations, although Obama’s was far more sophisticated. For example, the Obama team tied instant messaging to registration lists and sent texts to voters with not only campaign blurbs but also directions to local polling places. Obama posted twice as many YouTube videos as McCain, and also won the race for Facebook friends by better than 3-to-1.

Two years later Republicans began to catch up, effectively using social media in many of the 2010 midterm elections. Meg Whitman’s gubernatorial campaign in California was a particularly noteworthy digital showcase. Although she lost to Democrat Jerry Brown, the former eBay CEO aggressively used tech tools to press her case. Her website was personalized and written in each voter’s preferred language; her robotic phone calls were digitally programmed so that voters were greeted by their first names.

For the 2012 race, mobile messaging and Twitter will take on greater importance, with Democrats far ahead in harnessing the technology to raise money. ActBlue, launched in 2009, uses its Twitter donation service to collect money for Democratic candidates. After an initial credit card registration, donors can give to a campaign by tweeting out “donate $5 to [campaign].’’ Republicans have thus far failed with similar systems.

When it comes to the actual messaging function of social networks, both parties seem equally determined to compete in the rapid-fire, slimmed-down communication mode so fashionable these days.

But tweets about complex issues are as superficial as 10-second television sound bites, only less meaningful. For instance, this tweet from Mitt Romney: “It’s clear that Barack Obama did not follow the military’s advice for Afghanistan, putting the mission at risk.’’ Such bursts may be intended as social “headlines,’’ with more substantive messages to follow on other platforms, yet increasingly the 140-character pronouncements seem to be the content that much of the public focuses upon.

Obama, meanwhile, announced in mid-June that he would be writing his own tweets, but after a week all he had come up with was: “Being a father is sometimes my hardest but always my most rewarding job. Happy Father’s Day to all the dads out there.’’

In the recent New Hampshire debate carried by CNN, the host John King was relentless in urging viewers to send questions and comments via Facebook and Twitter. Yet not a single online question was used in the two-hour event. It was clear that CNN, like the candidates, seeks desperately to be connected to the new social order of communication, but hasn’t quite figured out how to make it meaningful.

The White House has reportedly received fewer tweets than it expected for today’s Town Hall, which underscores the fact that no matter how sophisticated the technology, there are only so many ways to ask, “Why is the deficit so high and the employment rate so low?’’

Digital campaigning is both potent and perilous for politicians since the quips and gaffes delivered by Twitter, Facebook, and YouTube last far longer than more serious pronouncements. How ironic that the most ill-advised utterances and images are those that will be most effectively preserved, forever, thanks to the digital process.

But whether they really embrace social networking, or simply tolerate it, none of the ’12 candidates will ever dare disclose, as McCain did in an interview just a few months before the ’08 election, “I am learning to get online myself, and I will have that down fairly soon.’’ He went on to concede, “I’ve never felt the particular need to e-mail.’’

It was so 2008.

(c) Peter Funt. This column first appeared in The Boston Globe.