Can a politician change their mind?

Greens Senator Dorinda Cox has switched from the Greens to the Labor Party, so is it okay for a politician to change their mind? 

Is switching parties ok? Or what about changing you mind on issues? And Jules has been fascinated with the case of Lucy Letby, the British nurse convicted of killing babies while working in a neonatal ward. 

It is also our birthday, so we celebrate Not Stupid turning one...with cake.