But that doesn't mean the effects of Facebook's efforts are not lopsided. Outside of Facebook's demographic particularities, there are reasons to believe that improved voter turnout in general helps Democrats, though there is a debate about this within political science.
In practice, though, there is no such thing as pure a get-out-the-vote, one whose tide raises all votes, and Facebook is no exception. It skews toward both women and younger voters, two groups which tended to prefer Democrats on Tuesday. Eighteen-to-29-year-olds voted 60 percent for President Obama, compared with 37 percent for Mitt Romney. The next-older age group, 30-to-44-year-olds, gave Obama 52 percent of their support. Among Americans older than 45, Romney won. The implication is clear: If Facebook provides a cheap and effective way to get more people to the polls, and it seems that it does, that is good news for Democrats. For Republicans, well, it's an uncomfortable situation when increasing voter participation is a losing strategy.
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Facebook's effect -- however big it is -- is at the margins, and in a country where elections are so close, the margins can matter a lot. But there are long-term trends underfoot that, for Republicans, mean their troubles go beyond Facebook. This year was the third presidential election in a row where young-voter participation hovered around 50 percent (meaning that half of eligible young people actually voted), Peter Levine of the Center for Information and Research on Civic Learning and Engagement at Tufts University told me, and this is up from a low of just 37 percent in 1996. Obviously, that sort of shift is not the result of a Facebook message. "This seems to be a significant generational change," he said.
The reasons for this generational change are complex and not totally understood. One certain factor is simply that recent campaigns have tried harder to reach out to young people. "In the 1990s the conventional wisdom was that young people don't vote," Levine said. "So they would literally look through a contact list of potential voters to reach out to, and just delete the young people -- not to discriminate but because they were trying to be efficient."
But that ended with what Levine calls the "50/50 nation situation" -- elections so close that campaigns could no longer afford to write off huge parts of the population. "It had already begun to change, but Obama won on the strength of young votes in '08 -- not only in the general election but especially in the primaries. They gave him Iowa. Without Iowa, no President Obama."
For years it was thought that one reason young people voted in such low numbers is because they are so mobile: If you don't live in a place for years, voting is, as political scientists term it, "costly." You have to reregister every time you move, find your polling place, and, if you plan to vote in local races, spend time getting up-to-speed on complicated municipal politics. But this calculus of inaction may be changing: With the Internet, it's much easier to find where your polling place is. And our online media environment privileges national politics over local politics so much, that national politics alone may entice more people to the polls.
Additionally, Constance Flanagan of the University of Wisconsin argues, there's been a backlash on college campuses to voter-suppression efforts. "The voter-suppression thing did make people more aware," she said. "Our university newspaper had a front-page story about what are your rights, do you have to produce an ID.... It was a conversation topic among young people and something they passed on to one another." Particularly, she said, that minority groups who felt targeted really responded by organizing themselves and making sure people voted. (Ta-Nehisi Coates and Andrew Cohen have both written about this backlash here at The Atlantic.)
Even with these recent improvements, Levine reminds us to bear in mind that we're still only at 50 percent, and the other 50 percent, those who are not voting, is not a random sample of the population -- typically they are lower-income, at lower education levels, and not into politics. With social media becoming an increasingly important part of political communications, campaigns and activists should ask whether there's any way to use social media to get to them. "I think we do incrementally, because there's some serendipity where your old high school friend gets into politics and draws you in, but does it happen at a large scale? I don't think we know," he said.
All of this adds up to a shifting electoral environment, as young people come out to the polls in greater numbers, and are more easily reached online. "In terms of good news for the Democrats," Donald Green of Columbia University told me, "the fact that you have this age cohort that has been socialized into very strong presidential support for Democrats, is in some ways the countervailing force to the age cohort that was socialized into strong Republican support under Reagan." Voting once is known to be habit forming. Those who were brought to the polls by the wave of enthusiasm for Obama in 2008 will likely vote in greater numbers for the rest of their lives, even in a more humdrum election, as this one felt.
And that's perhaps the worst news of all for the Republicans. A wave of enthusiasm is one thing, an anomaly in an otherwise 50/50 nation. But now the tide has gone out, and the seashore looks changed.