PARIS — The second wheel is starting to fall off Europe's political wagon.

After the center left suffered a working-class revolt against globalization and austerity, the mainstream pro-European center right is being shredded by voters demanding tougher action against migration.

Battered by a growing assault from the Euroskeptic populist right, moderate conservatives from Berlin to Paris and Rome are torn between trying to outbid their tormentors with anti-immigration rhetoric or sticking to a more liberal, pro-European message.

Neither recipe assures success, and many in the conservative European People's Party (EPP) fear a severe blow to their political group's dominance of the EU institutions in next year's European Parliament election.

In an "America first" world, resorting to "Germany first," "Italy first" or "Hungary first" identity politics and demonizing migrants strikes some ambitious politicians as more promising than milquetoast appeals for closer European cooperation.

A rebellion from within Merkel's coalition has the veteran chancellor hanging on the ropes ahead of next week's EU summit.

U.S. President Donald Trump has poured oil on the flames from across the Atlantic, damning German Chancellor Angela Merkel's free-trading, open-door centrism in incendiary tweets while his ambassador in Berlin has boasted that he aims to empower nationalist conservatives across Europe.

Merkel's decision in 2015 to open the door to more than a million refugees and migrants, many of them fleeing civil war in Syria, fueled the populism that is now threatening to topple her in the twilight of her chancellorship amid widespread fear of uncontrolled borders.

A rebellion from within her coalition has the veteran chancellor hanging on the ropes ahead of next week's EU summit, where the battle for the soul of Europe's center right will be played out before the cameras. Expect skirmishes over migration and asylum policy as well as the future of the eurozone.

Outflanked on the right

Mainstream center-right parties elsewhere in Europe are fracturing or being outflanked by right-wing populists riding a wave of hostility to immigration and Islam, and austerity fatigue.

In Italy, veteran center-right billionaire Silvio Berlusconi thought he could tame the extreme right by forging an electoral alliance with Matteo Salvini's anti-immigrant League and the post-fascist Brothers of Italy. Instead, his Forza Italia party was outpolled, then sidelined as Salvini joined forces with the anti-establishment 5Star Movement to form a government of populists.

In Germany, Merkel's Bavarian sister party, the Christian Social Union (CSU), fears losing its absolute majority in Bavaria in October due to the rise of the far-right, anti-immigration Alternative for Germany. German Interior Minister Horst Seehofer, the CSU's leader, is demanding that border police refuse entry to asylum seekers registered in another EU country.

Austria's center-right chancellor, Sebastian Kurz, who is governing in a coalition with the far-right Freedom Party, provoked a chill by calling for an "axis" of Germany, Austria and Italy to crack down on migration. He appeared not to be aware of the dark history of that term, which designated the alliance of Nazi Germany and fascist Italy in the 1930s.

In France, the leader of the conservative opposition Les Républicains, Laurent Wauquiez, has just fired his liberal deputy, Virginie Calmels, after she objected to an anti-immigration, Euroskeptical leaflet entitled "France must remain France" that he distributed without consulting the party leadership.

Dozens of historic Gaullists and center-right lawmakers have defected from Les Républicains in protest at Wauquiez's lurch to the right, which is aimed at winning back voters lost to far-right leader Marine Le Pen's anti-immigration National Rally (formerly National Front).

Political scientists still expect the EPP to be the largest group in the next European Parliament, but the center right is certain to lose seats.

In Spain, former Prime Minister Mariano Rajoy's Popular Party government was toppled this month over a corruption scandal. The party is losing voters to the center-right Ciudadanos party, which is vying to displace it as the champion of Spanish nationalism in the face of a separatist challenge in Catalonia.

Orbán ascendant

One big beneficiary of this trend is Hungarian strongman Viktor Orbán, who has cowed the media, the civil service and civil society, and is gaining ground across Central Europe with his illiberal majoritarianism. Far from being expelled from the EPP for his deviation from liberal values, as Dutch Christian Democrats recently proposed, Orbán emerged from this month's EPP congress stronger than ever.

Having struck an alliance with Seehofer's CSU, Orbán is positioning himself as the anti-Merkel leader of a nativist "Christian Europe." Jarosław Kaczyński's Law and Justice (PiS) party, which is busily dismantling judicial independence in Poland after purging the military, public broadcasters and the civil service, is a soulmate in the effort.

Orbán even allowed himself the luxury, in a speech ostensibly paying tribute to the late German Chancellor Helmut Kohl, of threatening to create a rival pan-European formation of like-minded anti-immigration Christian parties, but said he prefers to stay and help a renewed EPP "find its way back to its Christian democratic roots."

Political scientists still expect the EPP to be the largest group in the next European Parliament, but the center right is certain to lose seats and could end up neck and neck with the massed ranks of Euroskeptics, even if the populists do not form a single coherent caucus.

EPP floor leader Manfred Weber of the Bavarian CSU, who relies on Orbán's Fidesz party to help keep his group as the largest in the EU legislature, has toyed publicly with the idea of Kaczyński's PiS affiliating with the EPP after the election to make up the numbers. Poland's main opposition party, the liberal center-right Civic Platform, is an EPP member, but PiS is looking for respectability and a new family in Parliament after the departure of its main allies, Britain's Conservatives, next year.

Like Europe's decimated socialists, the center right faces challenges from new forces in the center as well as on the radical fringes, making its positioning even harder. The more the mainstream conservatives pander to right-wing populist gut politics, the more they risk losing moderate supporters of a liberal, open society.

Those voters could be seduced by French President Emmanuel Macron's centrist La République En Marche party, which is scouring Europe for allies to create a pro-European, pro-business, socially liberal reformist bloc capable of holding back the tide of xenophobia and nationalism.

While Europe's conservatives run their wagon into the ground, it may be up to the Macronistas to keep centrist, European liberalism on track.

Paul Taylor, contributing editor at POLITICO, writes the Europe At Large column.