In May 2017, when Emmanuel Macron arrived at the Louvre in Paris to celebrate his election as president of France, he took the stage to the European Union’s anthem, “Ode to Joy.”

With EU flags fluttering in the wind, Macron stood as the great hope of Europe’s liberals—the man who would reverse the tide of nationalism and restart the project of EU integration.

Two years later, Macron is mostly isolated.

Across southern and Eastern Europe, he has overreached in a series of high-profile confrontations, antagonizing potential partners in the process. At home, his elevated style has translated into haughty policy, triggering a backlash from voters.

Although Macron may be an extreme case, his struggles are emblematic of a broader trend across Europe. With one month to go before the EU parliamentary elections, euroskeptic parties are poised to capitalize on establishment missteps and emerge stronger than ever.

The question is no longer whether they will gain seats in the elections, but whether they will be strong enough to upend the EU altogether.

Ten years ago, Italy’s establishment considered the Northern League a local party of right-wing renegades—an annoyance to be endured, rather than a serious threat to be countered.

Today, the Northern League’s general secretary, Matteo Salvini, is the most powerful man in the country, dominating a coalition in which he serves as Italy’s deputy prime minister.

As the euroskeptics’ biggest star, Salvini sits at the center of a movement that stretches across the Continent. In fact, the election posters of France’s National Rally, which is running neck and neck with Macron’s En Marche, feature the party’s leader, Marine Le Pen, smiling side by side with Salvini over the slogan: “Our ideas are coming to power.”

As in the past, Salvini and Le Pen will have the support of allies in Austria, Germany, Holland, Denmark, Finland, and Belgium in the new parliament. Recently renamed the European Alliance of Peoples and Nations, this bloc is expected to double in size in next month’s elections.

Undoubtedly, such a showing will disrupt European politics. But to truly upend them, Salvini will need to recruit new actors into the fold. The biggest prize would be Poland’s ruling party, Law and Justice.

During a trip to Warsaw, Poland, in January, Salvini spoke of a “joint action plan that will feed Europe with a new blood, new strength, new energy.”

Every plan needs a certain amount of luck, however, and Salvini has benefited from fortuitous timing. Law and Justice is a member of the European Conservatives and Reformists bloc, which was founded by the British Tories.

In the wake of Brexit, the Tories’ electoral prospects are deteriorating and with it their strength in the European Parliament. Ryszard Legutko, Law and Justice’s most important member of the European Parliament, hinted at his party’s open mind moving forward.

“Leaving a strong group to join a weak group is a difficult political decision,” he said recently, “but leaving to join a group that is also quite strong and growing is less so.”

To date, Law and Justice has treated Salvini and his band of rebels as a bridge too far, however.

The prospective European Alliance of Peoples and Nations is teeming with politicians far too solicitous of Russia for the deterrence-minded Poles to join them.

Salvini’s second target is Hungary’s governing party, Fidesz, led by Prime Minister Viktor Orban. After a steady deterioration in ties, the establishment European People’s Party recently suspended Fidesz from its membership over a campaign poster that targeted the European People’s Party’s own commissioner, Jean-Claude Juncker. The European People’s Party stopped short of expelling Fidesz altogether, but the rift has raised questions about the Hungarian party’s future alignment within the European Parliament.

As Orban said in January, “The party structures, traditionally left or right, are being taken over by a different dimension—those for migration and against immigration.”

For now, Fidesz emphasizes its preference for the European People’s Party, content to nudge, cajole, and shape the parliament’s largest party from within, but Salvini has worked hard to court Fidesz over the past month, contrasting his admiration for Orban with the European People’s Party’s evident frustration.

For months, observers have watched Salvini’s courtship of Law and Justice and Fidesz closely. Now, unexpectedly, a third opportunity for Salvini to expand his coalition has appeared on the scene.

With Britain’s exit from the EU delayed, the country will most likely run elections for the European Parliament. Led by Brussels’ most reviled man, Nigel Farage, the newly created Brexit Party has shot to the lead in virtually every British poll.

Together with Farage’s former party, the United Kingdom Independence Party, these two anti-establishment euroskeptic movements are projected to emerge as the clear victors next month.

Le Pen has already floated a tactical alliance with Farage. “He is welcome if he wants to join,” she said recently. “Even if it might be just for a moment.”

If there is a theme to Europe today, it is its extraordinary diversity. There is a fine line between diversity and disunity, however.

As Salvini has doubtlessly discovered, pooling Europe’s right-wing euroskeptics into one camp is easier said than done. Most observers judge his odds at succeeding as very slim. From fiscal affairs to foreign policy, the Continent’s euroskeptics are divided by geography, temperament, and outlook.

Still, Europe has never been governed by one faction alone, but rather by cooperative arrangements between various groupings. If Salvini succeeds in aligning an enlarged base of euroskeptic groups, he will have driven a stake in the Macronist vision and drastically changed European politics.

What would follow is anyone’s guess.