State not red or blue, but purple

New Jersey, where Democrat Jon Corzine won the gubernatorial race on Tuesday, is commonly thought of as a 'blue state' but is more accurately rendered as a multihued patchwork of purple, according to a map released Wednesday by ORFE Department Chair Robert Vanderbei.

"It only took me 40 minutes to make it this morning since all the programs are already on my computer," Vanderbei said.

After the 2000 presidential election, Vanderbei and his ORF 201 students, unsatisfied with familiar red-and-blue election maps, devised a computational model to create a more nuanced political picture of the United States.

While standard maps color each state blue or red based on the party that wins more votes, Vanderbei divided the country into counties, each of which he assigned a shade of purple along a continuum from red to blue.

Solid red denotes that 100 percent of the votes favored the Republican candidate; solid blue shows 100 percent of votes favoring the Democrat.

Vanderbei said he did not foresee that his Purple America map would gain widespread recognition. Though his map escaped public notice in 2000, media outlets such as U.S. News and World Report published a version that Vanderbei created for the 2004 election.

"My original motivation was to conduct a fun computer exercise, and I was a little surprised that as a political concept the purple map became so popular," he said.

Vanderbei said he calculated another purple map for New Jersey this week simply because he could. He recognizes, though, that some viewers consider his work a public service.

In the 2005 election map, the bright blue counties closest to New York City — Hudson County and Essex County — voted most strongly Democratic, while nearly red Hunterdon County gave the most votes to Republican candidate Doug Forrester.

Vanderbei has not yet compared the data from 2000, 2004 and 2005 to see if there have been significant shifts in party support.

Vanderbei chose to partition his maps by county rather than by congressional district because he could not find free district-by-district data.

"Back in the 2000 election, USA Today posted county by county data that I used. I think it all comes from the AP wire, and I don't know why they split it up by county.

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Data for congressional districts could be used to show the effects of gerrymandering," he said.

Asked whether he intends to dabble again in applying math to political issues, Vanderbei, a mathematician by training, said, "It's probably a onetime thing, but it's always hard to predict."

After his Purple America map gained popularity, Vanderbei opened an online storefront at CafePress.com to sell shirts, mugs and other merchandise emblazoned with his purple opus.

Sales through the site have earned Vanderbei "thousands of dollars, but not tens or hundreds of thousands. It was worth the few hours I put into it," he said.