Cas Mudde's article on the Guardian is blatantly false propaganda.
Cas completely ignored the Occupy Movement, which was 100% Populist and not in the least right-wing or nationalist. Cas also doesn't even mention Jeremy Corbyn or Bernie Sanders, both of whom were lifted up by a huge groundswell that can only be rightly described as left-wing Populism.
Sanders might be called a nationalist but certainly not an ethnic bigot or racist or anti-immigrant. He should only be called a nationalist in the sense that he wants the People at home to be treated fairly rather than abandoned by government that aids and abets shipping jobs out of the country under the guise of free markets while it's all really about higher profit margins for the elite at the direct negative expense of labor, the environment, and democracy where those jobs are shipped.