But we aren't talking about any 'old thing' are we, we are talking about the most important aspect that the government provide for us. To suggest a law about the NHS is remotely the same as a law to discuss colours of buses or taxis is absurd and the sort of deflection that people make to avoid...
So you compare the NHS to London Taxi colour schemes , hope you don't need to have some medical treatment at some time.
It's called putting your money where your mouth is, so if the Tories say there is no threat to the NHS then it surely does no harm to reassure people by enshrining it law...