In 2004, Democratic presidential campaigns — particularly Howard Dean’s — showed that the Internet was poised to become a powerful campaign tool. In 2008, Barack Obama delivered on that promise, turning his website into a cross between a social network and campaign management software. In 2012, he’ll have to push the envelope even farther.

Obama will need to focus not only on the web, but on a variety of emerging technologies. A new SurveyUSA poll shows why:

Among respondents who do not use a home telephone (28% of registered voters), and who were contacted by SurveyUSA on their cell phone or other electronic device, Obama leads by 22 points. When the two populations are proportionally blended, Obama is up by 2 points, within the survey’s theoretical margin of sampling error. [SurveyUSA, via Political Wire]

Obama has a massive lead among cell-phone only households. To exploit that lead, though, he needs to be able to contact them. Pollsters and politicos are just starting to figure out how to deal with cell-phone only households; Obama needs to perfect techniques to do so by next year.

But it’s not just about getting in touch with people by cell phone. I think Obama’s lead among cell-phone-only households signals a generational gap. The crosstabs show that Obama leads big among younger voters, and I think that finding and the cell-phone-only finding are basically the same thing.

The trouble is, the youngest generation of voters is getting harder and harder to reach by traditional methods. The Obama campaign needs to innovate to come up with a variety of ways to reach them. Cell phone calls, social networks, smartphone apps, and location-based ads on mobile devices all have to be a part of the picture.

If Obama can turn out this hard-to-reach and hard-to-motivate group, he can win. But first, he has to get their attention.