It is hard to think of a better MP to take on the cause of assisted dying than Kim Leadbeater. She is energetic, engaging, persuasive and speaks like a normal human being. She has no tribal reputation, so there is no barrier to winning over Conservatives, and she has experience of horrifying personal tragedy: her sister, the MP Jo Cox, was murdered.
But it would be wrong to say it was Leadbeater who won this initial push to legalise assisted dying. Under the surface, the most important contribution has been the one made by ordinary people, an experiment in participatory democracy by stealth. In the end, that was what delivered such a comprehensive victory for the change at this stage.