SHE HAS outlasted two U.S. presidents, three French leaders, six Italian prime ministers and three British ones. Once again, German voters decided the woman they call "Mutti" (mother) knows best.

Angela Merkel's victory Sunday in national parliamentary elections means Germany's first female chancellor and daughter of a Lutheran pastor who grew up under Communism in East Germany, secures a fourth term.

Merkel, 63, extends her 12-year tenure as Europe's longest-serving democratically elected leader.

Her achievement is not just an exercise in political endurance, but also a triumph for her governing formula: pragmatic, centrist, fair. Merkel's win was tainted by the emergence of the Alternative for Germany (AfD) party, a right-wing nationalist group, as the country's third-largest, but her methods and manner were validated, experts said.

"She does her job. She does it quietly. She does it efficiently. The economy is doing fine. There has been no mood for change at the top," said Michael Wohlgemuth, an expert on political and economic affairs at the Berlin office of Open Europe, a think tank.

"Germans feel pretty good about themselves compared to our neighbours," he added.

Final results released Monday showed Merkel's Christian Democratic Union (CDU) and Christian Social Union (CSU) bloc won 33 per cent of the vote, enough to remain the largest party in parliament, but down from 41.5 per cent four years ago.

It was one of the CDU-CSU alliance's weakest post-war showings.

A poor performance by the Social Democratic Party (20.5 per cent), Merkel's current coalition partner, prompted its leader Martin Schulz to quickly rule out playing a role in any new government. That means the business-friendly Free Democratic Party and the Greens could take part. Forming a coalition could take days or even weeks.

Despite her success, Merkel may not be the outright leader of the free world many allies and liberal-leaning voices have hoped for against Trump's isolationist and combative Washington.

Germany's unique 20th-century history is too compromised for that. Merkel herself does not covet the role. Her policies and instincts are perhaps more conservative — she opposes gay marriage — than her admirers give her credit.

While her positions on climate change, immigration and social justice are the opposite of Trump's in many regards, they are also broadly supported by Germany's mainstream political groups, with the exception of the anti-Islam and euro-skeptic AfD.

Merkel may be celebrated and courted around the world as a defender of European values who will stand up to Trump's rhetoric on military action in North Korea, trade protection or an aggressive Russian President Vladimir Putin. But her chief domestic political rivals would not do anything differently.

In this sense, Germany is the leader of the free world. Merkel is along for the ride.

The strong showing for the AfD — finishing with 12.6% of the vote — complicates matters. There has been no right-wing party in Germany's parliament since the decade after the Nazis were defeated in World War II.

That means Merkel can expect political turbulence, a fact she acknowledged when she addressed supporters Sunday and vowed to listen to the "concerns and anxieties" of AfD voters.

With typical understatement, Merkel said had hoped for a "better result."

Germans are especially sensitive to any revival of the extreme nationalism that brought Adolf Hitler to power 84 years ago.

Merkel's re-election, nevertheless, showed she possesses that elusive political gold dust: luck.

Merkel has achieved something that has escaped nearly every other country in the West recently — she made Germany feel tranquil.

That comes despite Merkel's move to open Germany's borders to more than 1 million refugees since 2015, most of them Muslims fleeing war and poverty in the Middle East and Africa. She also came under attack for her commitment to the European Union that included successive bailouts for Greece and Britain's referendum to exit the EU. In addition, she fumbled major crises relating to Germany's all-important automotive industry.

"Germany is an oasis of calm and stability right now," said Joerg Forbrig, a Berlin-based scholar at the German Marshall Fund of the United States, a think tank. He attributed much of this to Merkel's steady leadership and Germany's consensus politics.

Michael Broening, a policy analyst in Berlin at Friedrich-Ebert-Stiftung, a political foundation aligned with the Social Democrats, said part of Merkel's success is because most Germans do not think the influx of refugees was a crisis that got out of hand.

"People are doing well. There just isn't this desire for fundamental change," Broening said. With the nation's unemployment rate at a record low — 5.7% in August — many voters were prepared to overlook social issues for economic ones.

But he also had a warning.

"Every time Trump spoke about or tweeted about Merkel, her popularity actually increased. But in eastern Germany, in the AfD strongholds, Merkel was regularly greeted by boos and angry whistles wherever she went," he said.

"One of the unintended consequences of the summer of 2015 (when Merkel allowed the flood of refugees) is the AfD. It will have repercussions for decades," Broening added.

That's what Alexander Gauland, one of AfD’s leaders, told supporters Sunday after the results. "We will go after them. We will claim back our country."