For thousands of idealistic voters young and old, the defeat of Cory Booker in Newark’s mayoral election will come as a disappointment. Mr. Booker’s campaign for reform attracted the support of New Yorkers — and New Jersey residents — of all colors and religions. It was also run with an openness to ideas that challenged the orthodoxy of the Democratic Party’s liberal wing. Mr. Booker was open to the idea of school vouchers, for instance, and he was not hostile to capitalism. His opponent campaigned with the lowest of racial appeals, caricaturing Mr. Booker as a “neo-black” politico spawned by right-wing foundations, as one can glimpse by the demeaning cartoon posted on the James campaign Web site and reproduced herewith.

Yet there is a history in American politics of losing candidates spawning winning ideas and winning candidates. The defeat of Barry Goldwater in 1964 was the beginning of the revolution that brought Ronald Reagan to the presidency. Less gloriously, but no less relevantly, two workers on the losing campaign of George McGovern in 1972 — Bill Clinton and Hillary Rodham — went on to bigger things. Mr. Booker’s margin of defeat, 3,500 votes out of 53,000 cast, is smaller than that of either Mr. Goldwater or Mr. McGovern. If his supporters resist discouragement and remain dedicated to political reform and civic improvement, Mr. Booker’s campaign will be remembered for years to come as a victory.