Nelson Polsby, one of the giants of American political science, died Tuesday in his home in Berkeley, California.

If you ever took an intro to American political science class, odds are that you read his work or bought one of the 11 editions of his classic, Presidential Elections, which he co-wrote with his equally influential colleague, Aaron Wildavsky.

Personally, I owe my own foray into political science – and my doctorate -- to Nelson. His book, Political Innovation, was a shaping influence on my own work on partisan change; my supervisor had his doctoral studies supervised by Nelson; and when it came time for my own doctoral exam, Nelson was my outside examiner.

Now, the oral exam – or viva voce – at Oxford is the ultimate hurdle in the long process of getting a doctorate. It’s the final defense of what you have written.

In preparation, I secluded myself at my college for a week, reviewing every possible piece of literature – as well as my dissertation. When it came time for my exam, I put on the obligatory “sub-fusc” dress – a black gown, white tie, and black suit (think a grown up Harry Potter), and made my way to the exam.

The internal examiner also was in the sub-fusc get-up, and we waited for Nelson. After a few minutes, Nelson came in. A large man, he was wearing worn out corduroys, heavily broken in topsiders, and an equally comfortable cardigan sweater. He plopped himself on the couch, and then the Oxford examiner said, “Nelson, you are supposed to be wearing sub-fusc.” To which, he responded, “I’m from Berkeley. You’re lucky I’m wearing shoes.”

Nelson was a great wit, conversationalist, and provocateur -- with intense academic rigor. When it came time for him to give his visiting professorship lecture at Oxford, Nelson argued that the single biggest variable to explain postwar American politics was air-conditioning (an argument he expanded in the book How Congress Evolves).

The death of Nelson Polsby, then, is a personal and academic loss, and I am afraid that it also marks the passing of a dwindling breed: the publicly-engaged political scientist.

As Kevin Mattson argued about the history profession in the last issue of Democracy is also true for political scientists: The field has devolved into intramural, technical arguments of little relevance to anyone outside of the field. Modeling City Council voting in 19th century Philadelphia may be interesting or even skillful, but it tells us little about the operation, strength, and promise of our democratic institutions. And even if there were insights gained from one’s scholarly work, there is little incentive to write or promote it for an elite or general audience.

Nelson was a political scientist who cared about politics. He studied it as it was practiced, offered his opinions, and got involved in the rough-and-tumble of public debate. His work had direct relevance on the issues of the day, and he helped journalists make sense of what was happening around them. Unfortunately, there are very few political scientists left with a comparable interest in and impact on national politics.

I would end this by wishing that Nelson should “rest in peace,” but as one of Nelson’s former students (and one of my wisest teachers) put it to me the other day, “no one who knew him ever saw him ‘at peace’.” And that’s why he was such a great teacher, scholar, and contributor to public life.