Leftist intellectuals are firmly convinced that Trump is a populist. And that accusation does make some sense. But a lot depends on what you think populism is. The general idea is that a populist adopts popular stances that in the end don't work or are destructive. That strikes me as a useful summary of Leftism.
So the term is usually narrowed down to refer to politicians who claim to represent "the people" in opposition to a ruling elite. Trump's attack on "the swamp" is clearly of that ilk. So which is it? Is populism inherently Leftist or is it just one approach to politics?
A useful approach to defining populism has been made by Joe Forgas a distinguished Australian psychologist who escaped Communist Hungary as a child. Given that origin, his sympathey for the Left is rather limited, unusually for a social science academic.
He equates populism with tribalism and notes that Trump appealed to Americans as a tribe: "Make America great". Forgas also sees the Left as hugely tribal, obsessed with all sorts of tribal identities: Homosexuals, feminists, blacks etc. The Left, too, create tribes with their propaganda.
So Forgas does create a coherent story about populism.
But I think he misses the wood for the trees. He overlooks what British conservative philosopher Roger Scruton devoted his life to pointing out: That patriotism and conservatism are two branches of the same tree. So it was not some sort of narrow tribalism that lay behind Trump's appeal but his conservatism generally.
Trump certainly was patriotic and wanted the best for his country but he also had a whole range of conservative ideas -- he was critical of abortion, he disliked feminism, he sidelined global warming, he was pro-Christian etc. And he most clearly saw the status quo as having some virtue and thought it should be changed only gradually.
Where most thinkers saw the transfer of American industrial jobs to China as desirable on cost grounds, Trump looked to the effect that was having on American industrial workers and tried to halt it. He taught us that money was not everything. Stability had value too
And another change that Trump vehemently opposed was the mass illegal immigration into America by people with very different traditions to Americans. He liked America as it was and wanted population change to be carefully controlled and limited
So "make America great" was only a general rubric for a whole range of conservative policies. He was a thoroughgoing conservative, the first such that Americans had seen in public life for a long time. And that is why he is widely loved by conservatives and widely loathed by non-conservatives. The Left could put up with wishy-washy conservative like George Bush but a real conservative shook them to the core. They had never before been confronted by a real conservative and that generated huge rage
So Trump was a populist in only an incidental sense. The breadth of his appeal was the voice he gave to conservatism across the board. The Left thought that their own limited view of the world was the only one. Trump showed them otherwise.