You might want to check out something like https://politicalscience.jhu.edu/faculty-books/the-hollow-pa... for a more detailed treatment of this
I’m sorry, but just reading the description of the book makes me suspicious. They talk about “hollowing out of the party system,” but then point to the GOP, instead of the party that’s was dominated for nearly the whole 20th century by ethnic political machines and clientism. The party system on the right works just fine. There is far more alignment between GOP voters and the current GOP leadership than between democrat voters and the current democrat leadership.
To put it differently, you characterized populism as a rejection of pluralism. And my point is that, insofar as populism has anything to do with pluralism, it’s more a rejection of the anti-democratic structures that have been installed to manage pluralism. Which just makes it democracy.