Photo by Jacob Sutton/Gamma-Rapho via Getty Images In early 1984, Tony Benn, who had lost his seat the previous year, sought a way back into parliament via the Chesterfield by-election. Peter Kellner, the New Statesman ’s political editor at the time, went to Chesterfield to assess what was widely seen as a challenge from Labour’s left to Neil Kinnock’s leadership. Victor Zorza, the Guardian ’s Kremlin-watcher from the mid-1950s to the mid-1970s was once asked to recall his worst misjudgement. “The Hungarian Uprising in 1956,” he replied; “I went to Budapest and was intoxicated by the atmosphere. I thought it would succeed. If I had stayed in London reading Pravda and Izvestia , I would have known it would fail.” Judging a by-election presents much the same problem: visiting the place provides ample evidence of atmosphere, the anecdotal views of “real” voters, and the horrors of the media circus. It is possible to be right about what is happening, but easy to be wrong.…