MAGDEBURG, Germany—The night after Donald Trump won the presidency, hundreds of backers of an anti-immigrant party whose success has shaken German politics gathered in the biting cold in this eastern German city and celebrated a new reality.

“Bravo, Mr. Trump, you get it!” state party leader André Poggenburg shouted from the stage last Wednesday, framed by the dark hulk of a 500-year-old Gothic cathedral. “Today, I must say, it is truer than ever: Merkel must go!”

“Merkel muss weg! Merkel muss weg! Merkel muss weg!“ the crowd chanted in response. “Merkel must go!”

Mr. Trump’s election is the second upset populist victory in the West this year, after last June’s antiestablishment Brexit vote in the U.K. With it, German Chancellor Angela Merkel, Europe’s most influential defender of postwar internationalism, finds herself further under siege.

The Continent’s populist tide has reached Austria, where an anti-immigrant candidate is polling strongly ahead of next month’s presidential election, and Italy, whose center-left premier could lose a constitutional referendum on which he has staked his career. Aides to Ms. Merkel think in France, nationalist, anti-immigration leaderMarine Le Pen could win next year’s presidential election. At home, lingering discontent with Ms. Merkel’s handling of the refugee crisis could spoil her Christian Democratic Union’s re-election bid next fall.

On Thursday, Ms. Merkel met in Berlin with U.S. President Barack Obama. In a subsequent news conference, they vowed to address concerns about globalization that have given rise to populist movements across Europe and the U.S. and helped propel Mr. Trump to victory.

“What unites us is the common conviction that globalization needs to be defined humanely and politically,” Ms. Merkel said. “There is no turning back from it.” She said Germany “will continue to cooperate with the new administration.”

Of all Europe’s mainstream politicians fighting populist insurgencies, Ms. Merkel is in the strongest position. She has relatively high approval ratings and a healthy economy. Allies and opponents agree, though, that she must persuade skeptical voters she can meet a growing pile of political, economic and security challenges at home and beyond.

Ms. Merkel, 62 years old, declined through a spokesman to comment for this article. Aides and allies said in interviews her playbook for pushing back the populist tide includes a reaffirmation of values such as the right to asylum, an admission of past mistakes and the pursuit of pragmatic steps to fix them.

Ms. Merkel is widely expected to announce in the coming weeks she will seek a fourth term in next fall’s election. Current polls show she would be favored to win, although she faces some of the same forces that carried Mr. Trump to victory.

David Fuller's view

Angela Merkel was arguably a good Chancellor for Germany during her first two terms.  However, despite her intelligence and humanitarian instincts, I would not say that she was a good leader for the EU.  She appeared not to fully understand or respect the cultural differences between European nations.  Additionally, she seemed blind to the widely discussed risks of a single currency, without the federal state which had little support among the populations of EU countries. 

History does not suggest that political leaders improve with multiple terms.  There are exceptions, of course, but too often leaders seeking multiple terms lose their political judgement, become out of touch with their electorate and even become autocratic. 

Most political careers end in failure and Angela Merkel appears to be on that course near the end of her third term as Chancellor.  Her open borders policy was naïve and soon deeply unpopular with the German population.  It was also an open invitation for criminals in human trafficking, leading to the financial exploitation of countless refugees, including children. Many of these people lost their lives after being cramped into frequently unseaworthy boats or rafts. 

Survivors have included genuine political refugees and the EU deserves credit for accepting these unfortunate people.  However, they have too often been indistinguishable from many thousands of illegal economic immigrants from North Africa and the Middle East.  In other words, people from very different cultures which are not easily absorbed in numbers.    

Against this background Mrs Merkel is now talking about seeking a fourth term.  I think this is unwise and she is very unlikely to be as popular and successful as she once was.

How should the UK approach Brexit negotiations in light of the important EU elections for France, Germany and Italy?

There may be a temptation to hold off, see what happens in the elections and bargain point by point in EU fashion.  Also, the UK Supreme Court may complicate the process if it blocks Mrs May in wish to declare Article 50. 

The EU is visibly unravelling, but the UK should not be waiting around in hope that this might provide a better environment for Brexit.  That would be counterproductive and look like weak, uncertain governance in the eyes of both former and new allies who would like to have mutually advantageous trade agreements with the World’s 5^th largest economy.  Prolonged uncertainty would not be helpful for UK business or any other firms which might consider opening offices or expanding their current operations across this country.  It would also deter talented foreigners from applying for positions where they could develop productive careers for both themselves and the UK economy. 

If not impeded by the Supreme Court, I maintain that the UK should trigger Article 50 without further delay.  The UK voted to leave the EU.  That means a return of full sovereignty for this country.  That will involve leaving the customs union and it will then be in the mutual interests of both the EU and the UK to create a bespoke agreement, allowing free trade to continue.  Psychologically, it will then be much easier to negotiate on the basis of what both parties have to gain rather than to lose.  

Here is a PDF of the WSJ article.