They come not to praise the union but to bury it. But while they wait for the funeral, they will hold well-paying jobs in its central parliament.
The elections for seats in the European Parliament were a festival across the continent for the rag-tag collection of right-wing and far right-wing euro-skeptic parties, some of which add a soupçon of anti-Roma, anti-Semitic or anti-Muslim commentary to their rhetorical stew.
And to keep the pot boiling they were joined by a sprinkling of leftist anti-Europe parties, from Germany to Italy to France, all of which want to dismantle all or part of the vast European structure.
The recipe was astonishingly successful. More worryingly for European leaders, the mostly weekend elections showed the skeptics are not just on the march, but seemingly about to storm the citadel.
In France the far-right National Front came first with 25 per cent of the vote while the ruling Socialist party slipped to just over 14 per cent; in Britain the United Kingdom Independence Party, UKIP, came first with almost 30 per cent, while parties in the ruling coalition came third and fifth; in Denmark an anti-immigrant party came first; in Hungary Jobbik, a far-right party with distinctly unsavoury views and a visceral anti-EU stance, came second with 15 per cent of the vote, in Italy the Five Star movement, a populist anti-Europe group with a comedian as its leader came second.
In Greece, Syriza, a leftist anti-Europe, anti-austerity party finished first and the neo-fascist Golden Dawn party picked up 10 per cent of the votes.
Even in Germany, the steady engine room of the European Union, the Alternative for Germany, a party created just a couple of years ago and which demands that Germany ditch the euro, picked up almost 7 per cent of the votes.
It finished just behind Die Linke, a party formed from the ashes of the former East German Communist party, which campaigned against Europe and the Euro.
Changed the discourse
But even before these earthquake-like results, the anti-Europeans had already triumphed. They had forced many mainstream parties to fight on their ground.
Britain's ruling Conservaties capitulated first: their leader and prime minister, David Cameron, last year promised a referendum on whether or not to stay in the EU if he's re-elected with a majority in 2016.
This had been a key plank in UKIP's platform ever since its leader, Nigel Farage, was elected to the European Parliament 15 years ago.
In France the National Front has been preaching a simple message ever since its founder, Jean-Marie Le Pen, became a European MP 30 years ago.
The party is now a dynasty. Its leader, Marine Le Pen, is the founder's daughter, and she proclaims, "Europe destroys, the nation protects," a war cry bolstered by demands for stringent controls on immigration to France.
It's a measure of the National Front's new weight that even before the vote France's former president Nicolas Sarkozy, a man already positioning himself to run again in three years, wrote an article calling for the ending of the agreement that allows for the free movement of people in most countries of the EU. He also called for a new restrictive approach to immigration.
No longer at the fringe
Up until this election, mainstream European leaders had generally dismissed these parties as an idiot fringe or a forgettable collection of nasty extremists — more annoying than important or dangerous. Their vote surge has exploded that complacent analysis.
In fact the leaders of Europe have revealed themselves all but bankrupt of ideas since the financial hurricane struck the world in 2008.
Europe's last big idea was the euro, the common currency that came into effect in 2002 and which is now used in 18 countries.
But the price of defending it in the wake of the financial crisis has been crippling austerity in half a dozen southern European countries, and massive unemployment in many others.
Another big European idea was the free movement of people across the continent and relatively liberal immigration rules allowing outsiders into Europe.
The election results across most of Europe can be seen as a resounding No by a growing minority to both these big ideas.
No longer can commentators laugh off a man like UKIP’s Farage as "the wacky neighbour in a sitcom, breaking the political monotony with some side-splitting anti-Romanian slurs."
Nor can they expect the penchant for outrageous and unsavoury comments by men like Le Pen (his latest outburst in this campaign was to suggest that the ebola virus could solve Europe's immigration problem) to cause these parties to self-destruct.
The voters who have flocked to these anti-EU parties have simply ignored their gaffes, ignored their leaders' professed admiration for Russia's Vladimir Putin, ignored their lack of ideas on so many aspects of social policy.
This was, of course, a protest vote, but without a coherent and strong response from Europe's mainstream leaders, that protest will only grow.
These once-fringe parties have now become a force that threatens the European status quo and, indeed, if they get their way, the European Union itself as it is now constituted.