In this razor-close battle for the presidency, the rival campaigns are fighting for every undecided voter, making record numbers of phone calls and door-to-door visits, but "a new front has opened in the 2012 election: the #hashtagwar," says Julianna Goldman at Bloomberg News. Last week during a Virginia campaign stop, for example, President Obama said that Mitt Romney was conveniently forgetting conservative policies and adopting moderate ones because he was suffering from "Romnesia." Within 24 hours, #Romnesia was trending worldwide on Twitter, and Obama's stump speech was suddenly big news. So new is the phenomenon that nobody knows how much such viral successes will matter on election day, Harvard professor Nicco Mele, who studies social media in politics, tells Bloomberg News, but so far "Obama is operating at a different order of magnitude than Romney just in terms of raw numbers." How does Obama's social-media impact differ from Romney's? Here's a breakdown, by the numbers: 

1000 percent
Growth of Facebook since the 2008 campaign

31.1 million
Obama's Facebook page "likes"

10.2 million
Romney's Facebook page "likes"

Times that two "Romnesia" posts on Obama's Facebook page were "liked" within 48 hours

Percentage daily growth in Romney's Facebook fans before the first debate on Oct. 3

Percentage daily growth in Romney's Facebook fans immediately after the first debate

1.2 million
New Facebook followers Obama gained in a burst last week following the second presidential debate

21.2 million
Number of Twitter followers Obama has

1.5 million
Number of Twitter followers Romney has

Tweets Obama's campaign sent out during the second debate

Times they were retweeted

Tweets Romney's campaign sent out during the second debate

Times they were retweeted

7.2 million
Tweets posted during the second debate that referenced the candidates and their televised clash

168 million
Facebook users in the U.S.

154 million
U.S. Facebook users who are old enough to vote

YouTube users following Obama

YouTube users following Romney

1.4 million
Obama followers on Instagram

Romney followers on Instagram

Percentage of social-networking-site users who say online communications are "very important" or "somewhat" important in keeping them informed on politics

Percentage who have "liked" material on politics or social issues posted by others

Sources: Bloomberg News, Computer World, Global Grind, New York Times

Read more political coverage at The Week's 2012 Election Center.