The Comparison When former GOP congressman Bob Barr launched a Libertarian bid for the White House last week, politicos recalled another intervention by a third-party candidate with spoiler potential. In 2000, Ralph Nader seemed to nick enough Democratic votes to harm Al Gore’s campaign. Could Barr do the same to Republican John McCain?

Why It Works Nader’s consumer-rights work and progressive platform attracted voters who saw Vice President Gore as a status quo Washington insider. Similarly, Barr’s antiwar credentials and evangelical roots may siphon off Republicans who are dissatisfied with either McCain’s patience in Iraq or his distance from the church.

Why It Doesn ’ t Nader got nearly 3 million votes in 2000; Barr’s Libertarian predecessor captured fewer than 400,000, so Barr has some galvanizing to do. And Nader was on the ballot in 43 states, while the Libertarian Party is currently on the ballot in only 28—and not in battlegrounds such as Pennsylvania, Virginia and Ohio.