Tracking the reds and blues

Keith Poole’s analysis of the political polarization of American voters made him a media darling during the 2012 election season

Tracking the reds and blues

Poole poses in front of a steam locomotive from the Gainesville Midland Railroad, now on display in Jefferson, Ga. The train was built in 1907 and presented to the city of Jefferson in 1959.

Keith Poole’s pioneering statistical analysis has been admired by political scientists for decades. This year, however, his notoriety moved beyond academia and into the mainstream media spotlight, and for good reason: Poole’s work not only changes the way we understand Congress and how it works, but it also raises the alarm of how Congress will address—or fail to address—an impending national economic disaster reminiscent of the Great Depression.

It was perfect election season fodder.

“We’re more famous than ever now,” says Poole, the Philip H. Alston Jr. Distinguished Chair in the School of Public and International Affairs’ Department of Political Science. “I think it’s finally broken through to the popular press because of all these bloggers, like [New York Times’] Nate Silver, [Washington Post’s] Ezra Klein. It spread and took off. Academics have known it a long time, and our work is in the textbooks starting around 2000, 2001.”

With Howard Rosenthal, politics professor at New York University, Poole in the early 1980s created NOMINATE, a statistical software package that analyzes congressional roll call votes through history—all 13 million of them cast since the first Congress in 1789. Poole and Rosenthal have developed updated versions of NOMINATE, most recently DW-NOMINATE (the DW is for “dynamic, weighted”), as technology has changed. The program (available at—which won the 2009 Statistical Software Award from the American Political Science Association, cited for being “a landmark in software development for political science”—precisely plots on a graph where legislators stand on any issue.

“To put it most simply, this data allows students of Congress to measure ideological distance between members of Congress,” says John Maltese, head of the UGA Department of Political Science.

One of Poole’s fall 2012 classes was an upper-level undergraduate course, “The Polarization of American Politics.”

NOMINATE was “the first comprehensive, constantly updated and objective measure of the ideology of individual members of Congress.” NOMINATE was also the first tool that explained the motivation behind the roll call voting decisions.

“This result changed political scientists’ understanding of why members of Congress vote the way they do, which was previously characterized as reflecting a chaotic mix of local interests and parochial concerns,” says Chris Hare, a Ph.D. student in political science and Poole’s graduate research assistant. “Instead, the bulk of congressional voting can be understood as an ideological struggle using the spatial model of voting.”

“Virtually everyone who studies Congress uses NOMINATE,” Maltese says.

Since the mid-1970s, Democrats and Republicans in Congress have continued to move away from the ideological center and toward their respective liberal and conservative poles. This trend can be seen in the graph (above), which shows the mean score of the Democratic and Republican parties on the liberal-conservative dimension in the House since the end of Reconstruction. NOMINATE scores (shown on the vertical axis) range from -1 (most liberal) to +1 (most conservative), with a 0 score representing the midpoint of the extremes (the most ideologically moderate position). Because the Democratic Party was split into North and South throughout much of this period, the means of both wings are shown separately on the graph.

Poole’s interest in politics began early. He was born in Newport, Ore., in 1947, to a carpenter-gunsmith father and schoolteacher mother. They moved often to pursue work, and their lifestyle was never affluent, living once without indoor plumbing and another time in a trailer behind a carpentry shop where Poole’s father worked.

He began reading the newspaper by age 7; by the eighth grade, he avidly followed the 1960 Kennedy-Nixon debates on TV. That year also marked his introduction to another lifelong passion: he got his first amateur radio license, which he has kept ever since (eventually holding the highest class of licensure, Amateur Extra Class, since 1969). He taught himself Morse code “with a telegraph key hooked up to a battery and a buzzer.”

In 1965, he began working his way through Portland State University, with unexpected results: he flunked out of classes, twice.

“I partied,” he says.

Poole decided he wasn’t college material and enlisted in the Army without his parents’ knowledge. He remembers the exact date when he went to Vietnam: April 2, 1968. He was nearly killed by Viet Cong rockets a month later. One of his good high school friends died in a separate incident near Saigon that July. From his base southeast of Saigon he saw countless body bags on their way home.

Photos and a Lionel model train sit on a shelf in Poole’s Baldwin Hall office. The photo of a young Poole in military wear was taken in March 1969 shortly before he left Vietnam. The other, taken in the late 1980s, shows him standing in front of a supercomputer at Purdue University, where he was working on the NOMINATE statistical method.

When he returned from Vietnam in April 1969, he had a new plan: use the GI Bill, return to Portland State and maintain a 3.85 GPA. After graduating with a B.S. in Political Science in 1972, he received both his M.A. and Ph.D. in political science at the University of Rochester. Before assuming the Alston Chair in 2010, he taught at the University of California, San Diego, the University of Houston, Carnegie-Mellon University and the University of Oregon.

A discovery he made in Rochester led to the unique visual component of NOMINATE.

While not the best student, Poole says, he immersed himself in cutting-edge econometrics and statistics and learned to write computer code. And then he realized something surprising.

“I can see things in my head,” he says. “I can visualize geometric things and move them around inside my head and look at them. I didn’t think I was Mr. Einstein or anything. It just finally dawned on me that I can see these things that other people can’t.”

To clarify: “I can visualize mathematical distribution and move it around, and then I put it into computer code to see if I’m right. Most of the time, it’s exactly right.”

The result is a graph that groups and color codes voters by ideology, making the ideological makeup and motivations of Congress very clear.

Voteview’s YouTube video, “Congressional Voting from 1789 to Present,” shows NOMINATE graphs in rapid chronological order, giving the impression of a living organism made up of small red and blue parts which are moving slowly around in an undulating cluster. But the big picture is clear: starting around the 1970s, the blues and reds separate more and more, spreading out and far away, with some of the reds meandering off into the wild. The cluster has become two disparate organisms operating independently. Congress is currently the most polarized along party lines it has ever been since the late 19th century, according to Poole.

Poole will address the effect of polarization on financial panics in his next book, co-written with Rosenthal and Nolan McCarty, politics and public affairs professor at Princeton University, Political Bubbles: Financial Crises and the Failure of American Democracy, expected to be released by Princeton University Press in April 2013. The book compares the response of America’s political system to the current financial crisis to that of the 1920s-30s, which occurred at a low point of political polarization.

There’s no expectation that Congress will respond to the current financial crisis nearly as well, Poole says.

“The news is not good,” he warns. “They failed.”

“The problems of the U.S. are so serious that we need broad-scale compromise. With extreme polarization, it’s very difficult to get politicians to behave as statesmen—we don’t have the Harry Trumans and Dwight Eisenhowers anymore.”

Poole was an infant during Truman’s term, but he remembers Eisenhower clearly, especially the 1956 election—his parents, Roosevelt Democrats, groused when an uncle declared support for Eisenhower.

UGA’s hiring of Poole, a member of the American Academy of Arts and Sciences and a faculty member in the highly ranked political science department at the University of California, San Diego, turned heads in 2010, Maltese says. In addition to his ongoing research and stature as a public intellectual, Poole has used his endowed fund to promote the department by sponsoring a steady stream of leading political scientists to speak on campus and has funded major conferences at UGA.

“This provides a vibrant intellectual atmosphere for our faculty, students and community, and it has done much to the raise the visibility of our department,” Maltese says. “The University of Georgia is a better place because of him.”

Jimmy Alston, president of the John Huland Carmical Foundation in Atlanta and son of Philip Alston, for whom Poole’s endowed chair is named, agrees.

“His specialty is how Congress votes; I can’t think of a more pertinent issue right now than that one,” Jimmy Alston says.

Poole has been fascinated by amateur radio since he was in eighth grade and has held the highest class of licensure since 1969. He keeps his equipment set up in his Athens home.

As for Poole, he says he likes living in the South, spending his free time with his wife and their six cats; researching and teaching about the political-economic history of railroads, another one of his abiding interests; and communicating in Morse code with longtime amateur radio friends for hours each day. While he calls himself “crusty and unusual” while discussing the foreboding political future, he includes a glimmer of hope in a later email:

“Things are bad now, but they will get better,” he writes. “Hang on and be optimistic.”

—Mary Jessica Hammes is a freelance writer living in Athens, Ga.

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Check out Poole’s website at The YouTube video of increased political polarization over time can be viewed at Want to give? Contributions to the UGA Department of Political Science can be made by contacting Sarah Baines at (706) 542-9661 or at (JavaScript must be enabled to view this email address).