“Populism” as a term was rarely used in the 20th century; it was limited to US historians describing, in highly specific terms, the original agrarian populists of the mid-19th century. Latin American social scientists (often Marxists) focused it primarily on the Peronists in Argentina. I only started to really engage with the term in the mid-1990s, while researching my dissertation on what was then still predominantly called “rightwing extremism”.

Populists aren't a silent majority – they're just a loud minority | Cas Mudde Read more

The German political scientist Hans-Georg Betz had just published what is still the best book on the topic, Radical Right-Wing Populism in Western Europe, and I dived into Leiden University’s library to find anything I could find on this odd term. The great British political theorist Margaret Canovan had written an excellent overview, simply titled Populism, in 1981, but argued that, while there were seven different subtypes, populism itself could not be defined.

So I delved deeper, trying to engage with the work of the late Ernesto Laclau, an Argentinian post-Marxist theorist, undoubtedly the most influential scholar of populism for academics and politicians alike. For instance, at a workshop in Brussels this summer, Rafael Correa, the former president of Ecuador, and broadly considered a populist himself, approvingly cited Laclau. Unfortunately, I was not as smart as Correa, and never really understood Laclau’s complex 1977 book, Politics and Ideology in Marxist Theory, so I decided to move on without the term.

I had noticed the growing use of Rechtspopulismus (rightwing populism) among German scholars, however. They were using the term to distinguish parties such as Austria’s Freedom party and the German Republicans from “extreme right” or “radical right” parties such as the French Front National or the Flemish Bloc in Belgium. This seemed to me to reflect a broader acceptance of these parties in mainstream society, rather than a difference in their ideologies.

In 2002 I moved to the University of Antwerp, where my graduate student Jan Jagers wrote a dissertation on populism that renewed my interest in the concept. In conversations with him, I developed my own definition, which aimed to synthesise the consensus underlying most existing definitions. In The Populist Zeitgeist, I defined populism as an ideology that considers society to be separated into two homogeneous and antagonistic groups, “the pure people” versus “the corrupt elite”, and which argues that politics should be an expression of the volonté générale (general will) of the people.

The article didn’t exactly take off. It was cited just nine times in 2005, 16 times in 2016, and 28 times in 2007. Most scholars, like me, continued to see populism as part of a broader “radical right” agenda and devoted little attention to its specific contribution. The rise of Silvio Berlusconi’s Forza Italia created a new subcategory, “neoliberal populism”. Incidentally, Betz had already distinguished between “national populism” and “neoliberal populism” in his 1994 book.

The great recession that followed the 2008 financial crash freed populism from the (radical) right. The rise of Syriza in Greece, and to a lesser extent Podemos in Spain, showed clear similarities with, but also fundamental differences from, the populist radical right. They shared a pro-people and anti-elite politics, but Podemos and Syriza were clearly part of the radical left, both in terms of ideology and subculture. As a consequence, the term “populism”, without any qualifiers, became integrated into both the academic and the popular debate.

But the use of the term truly exploded only in the wake of the Brexit vote and, particularly, Donald Trump’s election victory in 2016. Trump’s inauguration in January 2017 saw the biggest spike in Google searches for “populism” to date. Academic research on populism surged too, as is demonstrated in publications such as the 2018 Oxford Handbook of Populism.

Facebook Twitter Pinterest A Google Trends graph showing worldwide searches for ‘populism’ between 1 January 2015 and 1 November 2018. Photograph: Cas Mudde

While the term still lacks meaning in much of the public debate, the academic community is closer to a consensus than it has ever been. Most scholars use populism as a set of ideas focused on an opposition between the people (good) and the elite (bad), although they still disagree on whether it is a fully fledged ideology or more a political discourse or style.

Paradoxically, now that we finally agree on what we mean by populism per se, the “populist phenomenon” in practice is almost exclusively populist radical right. The much expected, and hoped-for, leftwing populist wave has not happened. And while intellectuals and pundits of the left keep assuring us that the only future is an inclusionary leftwing populism, existing leftwing populism has turned nasty in Latin America and and become much less leftwing (Syriza) or less populist (Podemos) in Europe.

Consequently, we increasingly talk about a general populism when we’re actually referring primarily, and often exclusively, to a specific populism. I have called this the populist radical right, rather than radical right populism, because it is a populist form of the radical right rather than a radical right form of populism. Ideologically, authoritarianism and nativism determine the populism, rather than the other way around.

As decades of research have shown, the prime ideological feature of this group of parties and their supporters is nativism, a xenophobic form of nationalism. It is not surprising then that the main consequence of the “rise of populism” is a battery of policies that restrict the rights of “alien others” – most notably immigrants, Muslims and refugees – not of “native” elites.

It is important that “populism,” or even “rightwing populism”, does not (again) become a term that softens, and thereby normalises, the ideology and impact of the radical right – let alone the extreme right, such as Golden Dawn, which is not even populist. Some people have argued that this is best done by abolishing the term altogether, which is the lazy baby-bathwater solution. It assumes that populism is irrelevant, rather than not dominant.

There is no doubt that populism explains part of the puzzle of the simultaneous rise of parties as diverse as the Five Star Movement in Italy, Podemos and Sweden Democrats. It is noteworthy that in the early 20th century, nationalism and socialism mobilised mainly as anti-democratic extremism, whereas at the beginning of the 21st century populists are mainly democratic but anti-liberal. At the very least, this shows that democracy (popular sovereignty and majority rule) is now hegemonic, whereas liberal democracy – which adds key features such as minority rights, rule of law and separation of powers – is not.

Whereas nativism is a revolt of the natives, against “aliens”, populism is a revolt within the natives. This revolt is caused much more by the emancipation of the citizenry, as a consequence of what the US political sociologist Ronald Inglehart called “cognitive mobilisation”, than by a particular change in the behaviour or demographics of the elites.

Sure, political parties have become almost completely detached from society, and few workers still sit in parliament, but there are fewer workers overall and few were truly influential within their parties in the past. Similarly, while corruption scandals are bigger and more frequent, this is largely because the media are no longer controlled by parties and there is more state to exploit.

Given that the causes of all these processes are structural, rather than incidental, they will stay with us for a long time. Even if anti-austerity and anti-immigrant anxieties decline in both support and intensity, politics and societies have come to terms with new expectations of, and relations between, “the people” and “the elites”. This is what populism is about – and it won’t be solved by further marginalising ethnic “others”.

• Cas Mudde is a Guardian columnist and the author of Populism: A Very Short Introduction