The line that got the most applause at the opening rally of the Liberal Democrat conference in Glasgow came from Nick Clegg, but it wasn’t about housing or tax or civil liberties or nuclear power. It was about the party itself: ‘People who don’t understand us like to call debate division. I think it is debate that gives us our unity.’ He said that after the Syria vote he’d told David Cameron: ‘It’s not a defeat, it’s just a reference back.’