(Bloomberg) -- When a 20-something YouTuber can create a viral sensation with a video proclaiming to “destroy” the politics of Chancellor Angela Merkel’s party, you know things aren’t going well for Europe’s most experienced leader.

In the week before Germans head to the polls -- when they may provide clues as to how long Merkel can hang on -- a blue-haired moderator, known as Rezo, unleashed an hour-long fusillade at Merkel’s Christian Democrats. Since its May 18 release, the video has been viewed more than 7 million times, with the “likes” outweighing “dislikes” 23 to one.

While the attack was dismissed by CDU officials as based on “pseudo-facts,” it’s a sign of the challenges gnawing at Merkel’s hold on power a year into her rocky fourth and final term. As she contends with strained relations with French President Emmanuel Macron and populist incursions across the region, the erosion of her authority in Berlin has hobbled Germany’s position within the European Union and beyond.

With the CDU’s support waning amid pressure from the anti-immigration AfD, her chosen successor Annegret Kramp-Karrenbauer has nudged Merkel to consider making way after Sunday’s vote for European Parliament and called a June 2 party conference in a bid to shake things up, people familiar with the matter have said.

The German leader’s biggest threat may come from the Social Democrats -- her reluctant junior coalition partner. Should the SPD suffer another electoral blowout, the party’s restive base -- which had to be pulled kicking and screaming into a third Merkel coalition -- may revive calls to break the alliance.

An even bigger test for the party will be in Bremen, a German city-state of 680,000 people that’s choosing a new government on Sunday. The North Sea port has been controlled by the Social Democrats since the end of World War II, and losing control of city hall could be a knock-out blow. Polls show the SPD in a dead heat or falling behind Merkel’s CDU.

To demonstrate she’s still engaged, the German leader has stepped up her public appearances in the days running up to the vote. She’s crisscrossed Germany to chat with students in Wuppertal, deliver a lecture on international politics in Ravensburg and open a fiber-optic network in her constituency near the Baltic Sea. On the campaign trail, she’s painted the contest as a choice between the common good and destructive nationalism.

“Our values mean that we can be proud of our country and at the same time work to build Europe,’’ Merkel told a crowd of 6,000 in Zagreb last weekend, alongside other centrist politicians. “There are populist currents that in many areas disdain these values, that want to destroy our European values.”

But the YouTube video -- entitled “The Destruction of the CDU” -- suggests she’s losing touch with a new generation, which makes her increasingly vulnerable to political attacks. Rezo, who traffics more in music and comedy productions, said he spent weeks looking into the impact of CDU policies and accuses the party of lying, compounding social inequality, failing to tackle climate change and fanning the flames of war.

“You always say that young people should get more involved in politics, so deal with it when young people think your politics are crap,” Rezo said in the video, which the CDU has taken seriously enough to plan a counter-production. But that might be too late for Sunday’s vote.

(This story is part of a series of “Postcards” from European capitals, which take a look at national implications of the vote for European Parliament.)

--With assistance from Zoe Schneeweiss.

To contact the reporter on this story: Patrick Donahue in Berlin at pdonahue1@bloomberg.net

To contact the editors responsible for this story: Ben Sills at bsills@bloomberg.net, ;Flavia Krause-Jackson at fjackson@bloomberg.net, Chris Reiter, Iain Rogers

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