How the Battleground Game Is Played

A primer on the concepts and tactics political strategists use to compete—and how this project was created.

This is an introduction to our Battleground 2016 series. The first story outlines what Donald Trump would have to do to win in the Rust Belt.

Regardless of local demographics, there are only three types of voters. Most have highly predictable partisan loyalties. Those who regularly vote comprise our base number, the minimum total of votes each candidate should be able to count on without really trying. Those who are party loyalists but not routine voters—active but infrequent enough that they cannot be reliably expected to cast a ballot, or too young to have developed the habit—are known as GOTV (or “get-out-the-vote”) targets: candidates don’t have to win them over, but will need to work hard to nudge, remind, and cajole them to actually vote.

In every state, the formula for victory can be expressed like this:


To be grossly generalistic, as Hillary Clinton would say, the parts of the election that put the candidate and surrogates front and center—the pageant of rallies, speeches, interviews, debates, and ads—are aimed at swaying the persuadables. The parts where campaigning is done by people anonymous beyond their own neighborhoods—especially the less-glamorous hodgepodge of phone calls, leafletting, and door knocks often referred to as “the ground game”—are designed to mobilize GOTV targets. Nearly every campaign engages in both persuasion and mobilization, albeit targeted at different audiences. (It is typically a mark of desperation when campaigns have to simultaneously persuade and mobilize the same voters to reach their win number—or engage in large-scale registration drives to expand their pool of available targets.) But the mix of those two approaches varies from state to state, depending on the nature of its electorate and the resources available to each candidate.

To understand how the campaigns will approach each state, and prioritize across them, we have attempted to mimic the process strategists use when developing a campaign plan. We turned to the same data sources political professionals use to profile the citizenry: voter files, the databases created from registration records and augmented by other intelligence on the electorate. (Scroll down for more on our partners in this project, Clarity Campaign Labs, and further detail on our process.)

Then we sorted voters into those five categories—each party’s base and GOTV targets, and the persuadables for whom both sides compete—and compared them to the number of votes that will be necessary to ensure victory in each state. How Clinton and Trump and their allied political machines get from their base to their win number in enough places to deliver 270 electoral votes—that is the whole campaign. The rest is commentary.

Battleground Guide FAQ

Where does this data come from?

We partnered with Clarity Campaign Labs, a Washington firm that specializes in targeting, analytics and polling for a range of Democratic and progressive clients. This fall, Clarity is working with a number of statewide and congressional candidates, but is not doing targeting on the presidential race for the Democratic National Committee, the Clinton campaign, or any of the outside groups working to elect her.

Where do they get their numbers?

The underlying information is from voter-registration records assembled and continuously updated by TargetSmart Communications, which manages the Democratic National Committee’s voter file. In many cases, we have tracked changes to local electoral rolls through the week before publication, accounting for new and changed registrants or voters who have moved. TargetSmart augments this with material from the U.S. census, other public sources like hunting licenses, and consumer marketers. In cases where information is not available—only some states, for example, require voters to include their race or ethnicity when registering, or allow them to identify with a party—Clarity develops statistical models that predict individual attributes. Other models we used predict the percentage likelihood than an individual voter will own a gun, have a college degree, or regularly attend church.

Where does the win number” come from?

It is just over half—50 percent plus one vote, to be exact—of the total votes likely to be cast for the two major candidates in a given state. Potential support for third-party candidates is factored into this calculation (see below for more details). If either Clinton or Trump reaches this number, he or she should be assured of victory, regardless of what his or her opponent is doing.

How do you know how many people will vote?

We projected the total number of votes we expect to be cast in each state, based primarily on multiplying a state’s total number of registrants by the average probability Clarity has calculated that each one will cast a ballot this year. (In most cases, the resultant total vote is a number comparable to 2012 turnout figures, while reflecting population growth and the differing intensity of each state’s campaign environment.)

How will third-party candidates affect this?

We set the win number based on a candidate’s share of the two-party vote, since the relative prominence of non-major-party candidates this year could mean that Clinton or Trump win battleground states without a majority of votes cast. To benchmark the number of votes we think could go to third party candidates, we averaged the 2012 third-party vote in every state with the current standing of Gary Johnson (Libertarian Party) and Jill Stein (Green Party) in four-way polling averages from RealClearPolitics. In states without current four-way polling, we used the average Johnson and Stein support from neighboring states. Before election day rolls around, we’ll explore the ways that Johnson, Stein, and even Evan McMullin could alter this math in specific battleground states.

How did you calculate each party’s base?

We counted voters whom Clarity’s statistical models profiled as having both strong partisan loyalties and a high likelihood of voting this year. In technical terms, this means voters predicted to have a more than 65 percent probability of identifying as either Democrat or Republican, and at least an 80 percent probability of casting a ballot.

How about in states, especially in the South, where a lot of registered Democrats never vote for Democrats for national office anymore?

Clarity’s models reflect a voter’s party registration, where available, but account for the interplay of hundreds of other variables, too, anticipating voting behavior rather than representing party attachments alone.

And what about GOTV (get-out-the-vote”) targets?

We used a 40-to-80 percent threshold to weed out those who are already probable to turn out and those who are extremely unlikely to vote. Typically, campaigns will focus their get-out-the-vote efforts on those in a middle range—effectively, those who do vote, but do so unreliably.

What is a persuadable voter?

We considered voters to be persuadable when they had a predicted partisanship in the middle range—between 35 and 65, on a scale where 0 is Republican and 100 Democrat—and at least an 80 percent likelihood of casting a ballot. 

How do you know that those voters are really susceptible to being persuaded by both sides?

We don’t, but we think this is a good way of estimating how many might be. Candidates in each state have access to their own internal polling, modeling, and research that further refines who a “persuadable voter” is, given the particular dynamics of their races. But our method allows us to quantify and define such people in a uniform language, so they can be compared across multiple states.

—With assistance from Andre Tartar. Special thanks to Clarity’s John Hagner and Cindy Sui for their work on this project.

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