^{by James Surowiecki}

1 The 2012 Presidential election laaks set to be, by a long shot, the most expensive ever. The Mitt Romney and Barack Obama campaigns (and their allies) have already spent more than four hundred million dollars on television ads, and are expected to spend six hundred million more in the next seven weeks. But the most important struggle between the campaigns is taking place elsewhere: in the hands-on, door-to-door fight for votes, called the "ground game". And, as Sasha lssenberg shows in his enlightening new book, “The Victory Lab", the ground game has been revolutionized in recent years by technological innovation and clever experimentation, to the point where it may well have a bigger impact on Election Day than all those millions in ads.

2 Even in today's money-soaked politics, all campaigns have limited resources of money, time, and manpower. Campaigns fail if they waste resources courting voters who are unpersuadable or already persuaded. Their most urgent task is to find and persuade the few voters who are genuinely undecided and the larger number who are favorably disposed but need a push to actually vote. Companies have long gathered data to break down their customer base into specific segments. Now political parties have become adept at micro-targeting, too, using data on shopping habits, leisure activities, voting histories, charity donations, and so on, in order to pinpoint likely supporters and the type of appeal most likely to win them over. ln the 2004 Presidential election, the Republican Party bought ads on the Golf Channel, because Karl Rove's data told him that golfers were more likely to support George W. Bush than John Kerry. And, as Issenberg documents, prospective Republican voters received different, and carefully targeted, versions of Bush's campaign positions depending on their neighborhood, or even their street: some were reminded that Bush was anti-abortion; others read about his pro-immigration positions. The 2008 Obama campaign was even more sophisticated, using a custom-built, constantly evolving algorithm that incorporated hundreds of variables in order to predict any given voter's allegiance and level of enthusiasm. lt sometimes seemed to campaign operatives that the algorithm knew what voters thought before the voters themselves did.

3 This kind of precision changes the nature of campaigning. lnstead of just flooding the zone with TV ads and hoping that the right people see them, campaigns can send flyers to only a few hundred people, say, or buy bus ads on one particular city line. Micro-targeting is hardly perfect, but when itmworks it allows campaigns to speak to voters directly and cost-effectively.

^{Adapted from The New Yorker, September 24, 2012}

^{(Note: This article was written before the 2012 U.S. Presidential election.)}

ln paragraph 1, the phrase "But the most important struggle between the campaigns is taking place elsewhere..." most likely refers to which of the following?