The struggling Tory leader ‘won’ the conference season with her headline-grabbing pledge to abolish stamp duty – as a difficult Budget looms, the chancellor must find a way to respond, says John Rentoul I t is what they call fox hunting season in Westminster, when parties race to steal their opponents’ best policies . To ‘shoot the fox’ is to spoil the hunters’ fun. It is a brutal and ruthless sport – and so far, Kemi Badenoch is winning. Her ‘fox’ – her pledge to abolish stamp duty – was a