Senator Lugar’s defeat isn’t really an unusual event. Senators have lower reelection rates than House members, in part because of their six-year terms. Whereas House members must constantly monitor shifting sentiments in their districts — exactly as Madison explained in Federalist 57 — senators are in greater danger of losing touch. That’s especially true when they’ve had some easy reelection campaigns. Twelve or eighteen years may elapse between real battles, which gives plenty of time for their electoral muscles to atrophy.

In 1980, a little-known Long Island official named Al D’Amato shocked the political world when he toppled Senator Jacob Javits in the New York Republican primary. Javits stood well to the left of the state’s primary electorate, and was in poor health. But he probably would have survived if he had spent more time in the state. I knew he was doomed when he told a television reporter about all he had done for upstate communities such as “Hoosier Falls.” The reporter corrected him: “You mean Hoosick Falls.”

Senator Lugar is a good man with a distinguished career. But he hadn’t actually lived in his home state for many years, and his reelection team failed to mount a state-of-the-art campaign. And so he lost.

Politics, like show business, can be cruel to aging stars.

— John J. Pitney Jr. is Roy P. Crocker Professor of American Politics at Claremont McKenna College.