I don’t see anything wrong with populism, per se. But establishment types sure act as if it’s a gateway to fascism. And they just make claims without reasoning why this is so.
The funny thing is, their job is 1.) upholding the constitution, and 2.) fulfilling their constituency's desires.
No.2) is more or less exactly what populism is.
The fact anyone takes issue with this, as long as it isn't in conflict with 1, baffles me.
And while on an academic level that is one aspect of fascism, fascism isn't inherently bad its self, it's only bad if the views it's reinforcing are bad.