The popular vote was an accurate predictor of delegate counts.

Who's winning, who's losing, and why.
June 6 2008 7:27 AM

Slate's Delegate Calculator

The popular vote proved an accurate predictor of delegate counts.

Illustration by Mark Alan Stamaty. Click image to expand.

With the dust settling on the Democratic nomination, it's worth a retrospective look at how successfully our calculator was able to estimate delegate counts based on a state's popular vote. While most states allocate the majority of their pledged delegates based on district-by-district vote totals, the proportion of delegates won by each candidate has historically been very similar to the statewide popular vote. This was the fundamental assumption of our calculator.

Advertisement

Of the 16 contests the calculator adjudicated after launching in early March, predictions based on the popular vote were off by an average of only 1.9 percent. Six states and territories reported final delegate tallies that exactly matched the calculator's prediction: Vermont, Wyoming, Guam, Indiana, Oregon, and Montana. The calculator was least successful in predicting Texas, which might be expected due to the state's Byzantine primary system.

Slate would like to thank the dozens of readers who wrote in challenging our numbers and suggesting new features for the calculator over the course of this project.

  • The current number of pledged delegates comes from NBC News' tally. The delegate count prior to March 4 includes the 14 pledged delegates from the Democrats Abroad Global Primary  and subsequent convention, who count for half as much as their domestic counterparts'.
  • We estimate the number of delegates based on the overall state vote, even though delegates are awarded by congressional district as well. We felt comfortable making this approximation because in the primaries through Mississippi, there was only a 2.9 percent deviation between the percentage of the overall vote and the percentage of delegates awarded in primaries. The proportion of delegates awarded by congressional district, therefore, does not differ greatly from the statewide breakdown.
  • The calculator does not incorporate superdelegates into its calculations. Superdelegates are unpledged and uncommitted and therefore can change their endorsements and convention votes at any time. As a result, we've simply noted at the bottom of the calculator how many superdelegates the leading candidate needs to win the nomination in a given scenario.
  • All of the calculator's formulas and data come from Jason Furman, the director of the Hamilton Project at the Brookings Institution.

Chris Wilson is a Slate contributor.

TODAY IN SLATE

Politics

Blacks Don’t Have a Corporal Punishment Problem

Americans do. But when blacks exhibit the same behaviors as others, it becomes part of a greater black pathology. 

I Bought the Huge iPhone. I’m Already Thinking of Returning It.

Scotland Is Just the Beginning. Expect More Political Earthquakes in Europe.

Lifetime Didn’t Think the Steubenville Rape Case Was Dramatic Enough

So they added a little self-immolation.

Two Damn Good, Very Different Movies About Soldiers Returning From War

Medical Examiner

The Most Terrifying Thing About Ebola 

The disease threatens humanity by preying on humanity.

Students Aren’t Going to College Football Games as Much Anymore, and Schools Are Getting Worried

The Good Wife Is Cynical, Thrilling, and Grown-Up. It’s Also TV’s Best Drama.

  News & Politics
Weigel
Sept. 19 2014 9:15 PM Chris Christie, Better Than Ever
  Business
Moneybox
Sept. 19 2014 6:35 PM Pabst Blue Ribbon is Being Sold to the Russians, Was So Over Anyway
  Life
Inside Higher Ed
Sept. 19 2014 1:34 PM Empty Seats, Fewer Donors? College football isn’t attracting the audience it used to.
  Double X
The XX Factor
Sept. 19 2014 4:58 PM Steubenville Gets the Lifetime Treatment (And a Cheerleader Erupts Into Flames)
  Slate Plus
Slate Picks
Sept. 19 2014 12:00 PM What Happened at Slate This Week? The Slatest editor tells us to read well-informed skepticism, media criticism, and more.
  Arts
Brow Beat
Sept. 19 2014 4:48 PM You Should Be Listening to Sbtrkt
  Technology
Future Tense
Sept. 19 2014 6:31 PM The One Big Problem With the Enormous New iPhone
  Health & Science
Medical Examiner
Sept. 19 2014 5:09 PM Did America Get Fat by Drinking Diet Soda?   A high-profile study points the finger at artificial sweeteners.
  Sports
Sports Nut
Sept. 18 2014 11:42 AM Grandmaster Clash One of the most amazing feats in chess history just happened, and no one noticed.