This, as Slate’s Sasha Issenberg has written about, allowed the brain trust in Chicago to conduct scientific experiments, testing new messages and new tactics and actually measuring their effects in real time. Combined with more traditional methods of campaign research and microtargeting, OFA 2012 had a treasure trove of data to work with to ensure that it was getting the right message, to the right people, in the right way.

Campaigns – especially at the presidential level – are far too complex and multi-layered to be able to say definitely that the Obama field program was the decisive factor in his big win.  It’s also far too early to be able to make conclusive cause-and-effect statements.  Here is what I can say with some measure of confidence:

1. Ensuring the success of early voting is now the most important element of the Democratic get-out-the-vote effort – and monitoring, tracking, and boosting the early vote is uniquely suited for the ground game.  Obama’s margins in states like Iowa and Ohio were boosted by weeks of “chasing” outstanding vote-by-mail ballots with multiple calls and door knocks, organizing shuttles from college campuses or African American churches to early vote locations, and relentless focus on turning out sporadic-voting Democrats and left-leaning independents who were supposed to have “lost enthusiasm” since 2008.

Expanding the electorate through voter registration is something that cannot be done with ads or direct mail – it’s painstaking work that requires a real investment in human resources.  In most campaigns, registration is typically considered last among the trinity of possible field strategies; it’s extremely work intensive, and newly-registered voters still have to be turned out come election time.  On a presidential campaign, devoting field resources to registration is even more rare because it can more easily be outsourced to third party groups than persuasion or even GOTV.

OFA did not accept this conventional wisdom, and early in the campaign decided to change the electorate through brute grassroots force – to the tune of 1.8 million new voters in battleground states.  The tens of thousands of new Obama voters that OFA registered in places like Colorado and Florida were the margin of victory yesterday, and all the credit should go to the people on the ground who ground through that thankless and difficult task.

2. The great, unwritten story of the Obama campaign is its revolutionary use of data and quantitative analysis, led by Chief Analytics Officer Dan Wagner.  What makes what Wagner and his team did different from Nate Silver’s FiveThirtyEight blog is the access to a wealth of inside information, including data generated by a field team that could provide near-instant feedback and conduct live experiments. In the same way that Howard Dean’s 2004 campaign showed the power of online organizing and fundraising, Obama 2012 has shown the power of analytics-based campaigning and the importance of a ground game to reinforce it.

Building a grassroots field organization requires playing a long game, and the return on investment often isn’t seen until the waning days of a long campaign.  Data analysis is esoteric and unsexy work that is largely (and understandably) misunderstood by the press and public, myself included.  But in my opinion, the Obama 2012 campaign has shown that “people-centered” and “data-driven” are no longer buzzwords; they might be the last best hope for future campaigns to break through the cacophony of ads, polls, and cable news chatter.

I want to be very clear: field organizing alone does not win an election.  Even the best people-centered and data-driven program cannot overcome a poor candidate, a poor message, or events or macroeconomic trends that are out of a campaign’s control.  But as we move into a midterm cycle in which Democrats are going to have to buck historical trends if we want to take back the House and hold onto the Senate, it will interesting to see if and how downballot candidates embrace the ground game.

I believe they can and should, with a few caveats.  First, organizing requires commitment – field is often the first thing on the budget chopping block, but an understaffed, under-resourced field campaign is worse than none at all.  Second, organizing requires time – candidates have to decide early if they will embrace a grassroots strategy and start to execute at least a year before Election Day.  Third, organizing requires talented staff – luckily for Democrats, there are thousands of young campaign veterans who have been brought up through the crucible of the 2008 and 2012 campaigns and who believe to their core in the power of this kind of politics.

With a real commitment, an early start, and a talented staff, candidates for non-presidential races can build their own people-centered, data-driven campaigns.  Interestingly, while OFA will almost certainly continue its work on behalf of the administration in the second term, Obama’s army of trained neighborhood team leaders are out there waiting to be courted by the next candidate to capture their imagination.

Addisu Demissie is co-founder and principal at 50+1 strategies, a California-based political consulting firm. He was previously national political director at Organizing for America. You can follow him on Twitter @asdem.