Whatever the outcome, the last two weeks have left the chancellor badly damaged and many Germans wondering how much longer she will last.

They have exposed the spectacular weakening of a leader who not long ago was seen as a key defender of liberal values — a sentiment that culminated in her decision in 2015 to welcome to Germany hundreds of thousands of migrants from the Middle East, Africa and elsewhere who were not wanted by neighboring European countries.

Three years later, as nationalism and populism take root in various corners of Europe and Germany itself, observers say Ms. Merkel is a political dead woman walking.

“Merkel was synonymous with the liberal world order,” said Andrea Römmele of the Hertie School of Governance in Berlin. “She was an authority at home and abroad, but that is history.”

“If she doesn’t go down now, she goes down in the next crisis,” Ms. Römmele said.

Over the last nine months, Ms. Merkel has stumbled from one political crisis to another. In the September election, her party saw a significant decline in voter support and a far-right party entered Parliament for the first time in more than 60 years. In November, a first attempt at forming a coalition broke down. Earlier this year, a second attempt hung in the balance for weeks. In the end it took Ms. Merkel nearly six months to form a government.