For an American, especially, it is impossible to witness the growing excitement here over Jeremy Corbyn’s candidacy for the leadership of the Labour Party without being reminded of Berniemania. Though Corbyn, at 66, is more youthful than the 73-year-old Vermont senator, and entered Parliament as MP for Islington, in north London, back when Sanders was still in his first term as mayor of Burlington, the two mavericks share a reputation for putting principle ahead of popularity, a willingness to challenge their own party’s conventional wisdom—especially on the economy—and an improbable status as icons of authenticity in an age of sound-bite politics.