Re: why what worked for Trump won't work for Sanders ... left and right populism are not the same.
Right wing populism is chaos linked by reactionary sentiment, that's why it can unite Christians, libertarians and nativists, as well as people who just want to slam the handbrake on and believe illogical things like that it's possible to reverse economic globalisation. It doesn't have to create anything or imagine anything, the things it thinks about are in the historical record.
There's an element of reaction in the broad left, lots of desire to return to a Fordist style social covenant that's never coming back in the US, but ultimately a popular left movement is about creating new institutions and doing difficult things. It requires trust and is harder to build, and you can't do it using unpredictable though charismatic megalomania in the Trump or Berlusconi vein.
We need a Green New Deal (even if I don't like that form of words) quite desperately in Australia, but our politicians are venal party mannequins, and there isn't a decent one on our Labor frontbench.