If you’ve ever watched a politician promise you a three-course meal only to hand you a single stale budget-brand biscuit, you will recognise that exact sinking feeling I get whenever Andy Burnham opens his mouth. Andy Burnham: not sensible For years now, he’s been held up as Labour’s great sensible left hope – the man who stood up for the north, who’d take on the Westminster machine, who might just drag the party back to its working-class roots without scaring off anyone who owns more than one house. It’s a great story. It’s also about as believable as a government minister…