IE 11 is not supported. For an optimal experience visit our site on another browser.
The first voters of the day begin filling out their ballots at a polling site in Brooklyn, N.Y., on Tuesday.
The first voters of the day begin filling out their ballots at a polling site in Brooklyn, N.Y., on Tuesday. John Minchillo / AP

Midterm elections roundup: How the Decision Desk calls races

Once polls close, the work for the NBC News Decision Desk begins.

By , and

Once the polls close, there’s nothing for the voters to do but wait. But the fun will just be starting for the National Election Pool and the NBC News Decision Desk. Their hard work helps NBC News project the results of every election, so it’s worth understanding how it all works.

Data reporters will be conducting exit poll interviews, and collecting vote results across the country alongside the counts that come in from local officials. Then the Decision Desk does some quality-control work to make sure the data is accurate, before analyzing that data.

When will the Decision Desk project a winner of a race? Not until it is 99.5% certain of its projection. Until then, you may hear some other projections:

Too early to call: Either there’s not enough data to project this race, or a candidate’s lead still hasn’t met the statistical standards to warrant a projection.

Too close to call: This is a signal from the Decision Desk that the final margin will be less than 5 percentage points. 

Apparent winner: The Decision Desk has projected a winner, but the race is “close enough that the outcome may depend on a potential recount and/or confirmation that the results that have been reported are accurate.”

Elsewhere on the campaign trail:

North Carolina Senate: National Journal reports from Rocky Mount on Democrat Cheri Beasley’s attempt to run under the national radar and score an upset in the state’s open Senate seat. 

Nevada Senate: Nevada Democratic Sen. Catherine Cortez Masto makes a final push with Latina voters amid fears Democrats may struggle with those voters, NBC News’ Natasha Korecki reports from Las Vegas. 

Ohio Senate: NBC News’ Jesse Kirsch speaks with young, independent voters about the economic choice facing them as they decide who to back in Ohio’s Senate race.  

Pennsylvania Senate: The big news out of Pennsylvania is a new lawsuit from Democrats, including Democratic Lt. Gov. John Fetterman’s Senate campaign, asking a federal court to overturn the state Supreme Court’s recent decision that undated or misdated ballots should not be counted. Meanwhile, NBC News’ Allan Smith reports on how Republican Mehmet Oz is preaching bipartisanship on the trail (and how Democrats are needling those calls). 

Ohio-13: The Washington Post reports on this swing House race between two millennial women.

Oregon-05: The New York Times explores how the Democrats are struggling to win this seat after Rep. Kurt Schrader lost his Democratic primary (Schrader himself hasn’t endorsed in the general election). 

Texas-28: Former President Bill Clinton traveled to South Texas to campaign for Democratic Reps. Henry Cuellar and Vicente Gonzalez, and Democratic House candidate Michelle Vallejo, NBC News’ Suzanne Gamboa reports.