On Wednesday, to the surprise of many, Thomas Kemmerich, from the liberal Free Democrats (FDP) was elected state premier of Thuringia with the help of the far-right party — a first in postwar German history. European parliamentarian Jörg Meuthen, who also serves as Alternative for Germany (AfD) co-chair, was pleased: He told the German daily Frankfurter Allgemeine Zeitung that his party now formed a "bourgeois circle" with Angela Merkel's Christian Democratic Union (CDU) and the FDP in the state.

Though the ensuing outcry led Kemmerich to resign and dissolve state parliament on Thursday, the AfD can congratulate itself on having joined the "bourgeois" big leagues.

Martin Schirdewan, an MEP from the Left Party, described the cooperation between the CDU, FDP and AfD that led to the surprise result as the "breach of a taboo.” For Europe's far-right populists, who now form the fourth-largest faction in the European parliament — the far-right Identity and Democracy (ID) group —  this represents another breakthrough, reflecting a trend that has been developing all over the bloc for years. Until Wednesday, Germany was an exception.

Read more: What's happened in Thuringia, and why the outcry?

Though there have been some setbacks recently — in Italy and Austria, for example — far-right populists in many countries across the continent are either in government, the largest opposition party, or have helped to significantly weaken the established mainstream parties.

Despite Kemmerich's resignation, the results in Thuringia will give a boost to the AfD and ID, which includes Matteo Salvini's Lega, Austria's scandal-ridden Freedom Party (FPÖ) and Marine Le Pen's National Rally (RN) a boost.

The far right 'normal' in Austria

In Austria, the FPÖ has already participated in government at federal level several times. The Christian-democratic Austrian People's Party (ÖVP) moved closer to the FPÖ's positions under its "flexible” leader Sebastian Kurz, embracing the far-right populists. The FPÖ has also been represented in various state governments. Even the Social Democrats had entered a coalition with the FPÖ in the state of Burgenland before last year's "Ibiza affair" led to the collapse of the governing coalition. A secretly recorded video showed FPÖ leader Heinz-Christian Strache being apparently receptive to proposals involving underhand political practices made by the supposed relative of a Russian oligarch.

On Thursday, referring to the widespread criticism of the CDU and FDP for cooperating with the AfD and blurring the line of divide with the far right, the FPÖ politician Herbert Kickl said: "This is a quasi-totalitarian and distorted depiction of democracy, delivered by its self-appointed keepers."

Read more: Austria's Kurz threatens to veto EU post-Brexit budget

Fewer inhibitions in Italy

In Italy, the lines between the Christian Democrats, the conservatives and the far right have long been blurred. Ex-Prime Minister Silvio Berlusconi's conservative Forza Italia is cooperating very openly with the far-right Lega (League) and the neo-fascist Fratelli d'Italia to beat the anti-establishment populist Five Star Movement (M5S) and the Social Democrats in the next elections.

Former Interior Minister Matteo Salvini is very popular, even if his Lega did not do as well in the recent regional elections in Emilia-Romagna as he would have liked. There is no doubt that the "breach of a taboo” happened a long time ago in Italy, with the far right in power in many villages, towns and even regions.

Read more: Italy's 'Sardines' movement presents ethical counter to far right

The far right is everywhere

In France, the far-right National Rally is also expected to do well in March's municipal elections. In the hope of earning more respectability, its leader Marine Le Pen changed the Front National's name two years ago — a strategy that appears to have been successful. Her party has benefitted from the fact that the country's more established conservative parties have lost much of their credibility and got caught up in in-fighting and is already in power at local and regional level. Le Pen is hoping to beat incumbent President Emmanuel Macron in 2022. He beat her in the last election but a poll last autumn put her ahead of him in the next one. Nobody in France would be shocked by what happened in Thuringia any more.

In Spain, the conservatives and far-right Vox party have already formed a coalition in Andalusia. Vox is becoming increasingly mainstream and is now the third-strongest camp at national level. In the Netherlands, Prime Minister Mark Rutte of the People's Party for Freedom and Democracy has two far-right parties to worry about. While in Belgium, where there hasn't been a government for 14 months, the strongest party is the right-wing populist, Flemish nationalist Vlams Belang. In Finland, the far-right populists are close behind the Social Democrats and have already been part of the government before. In Switzerland, Poland and Hungary, nationalists and populists are in power and have large majorities. And the list goes on.

AfD a complex variable

And what about Germany? The AfD started out as a eurosceptic party during the financial crisis and moved further and further to the right until it became an anti-immigration party. It is now the largest opposition party in the Bundestag.

For the moment, it seems as if this week's events in Thuringia were no "accident" — and neither the CDU nor the FDP want to allow AfD to hold power or play kingmaker in Thuringia or elsewhere.

However, there is nothing to prove that Germany will not go the way of other countries in Europe. The major established parties are losing their power and significance; parties on the margins, especially the far right, seem to be unstoppable. Setbacks such as those in Austria or Italy recently might slow down their progress, but cannot stop them completely.