By Alexandra Hudson
BERLIN (Reuters) - Philipp Roesler, the young leader of Germany's Free Democrats (FDP), looked like a dead man walking at the start of the year, until he took a major risk that turned his and his party's fortunes around.
His party, which shares power with Angela Merkel's conservatives, was in freefall, and rivals were planning a putsch, fearful the FDP would be booted out of government in a September election with Roesler at the helm.
Then, the man many in Berlin had dismissed as a political lightweight, caught the plotters on the hop by offering to resign, a day after the FDP had confounded pollsters by doing well in a regional vote. They backed down and pledged their loyalty instead.
The FDP and Roesler have been on the mend ever since. Recent opinion polls put support for the FDP at 6 or 7 percent, up from just 2 percent a year ago, and above the 5 percent threshold needed to win seats in parliament.
That is still a far cry from the record 14.6 percent the party received in 2009. But it is thanks to the recent revival that Merkel can hope to continue her center-right coalition after next month's vote, instead of being forced into an awkward partnership with her left-wing rivals.
"Roesler took a gamble and won. That has boosted his approval ratings," said Peter Matuschek of pollster Forsa.
Founded in 1948, the FDP has been in government with either the left or right for 46 years of the Bundestag's 63-year history. Party luminaries include Hans-Dietrich Genscher, who served as foreign minister for nearly 20 years, helping bring about German reunification under then chancellor Helmut Kohl.
Four years ago its record score helped Merkel cruise to a second term. Then the troubles began.
The business-friendly party alienated supporters by breaking its campaign promise of tax cuts. And its leader at the time, foreign minister Guido Westerwelle, was lambasted for siding with Russia and China and refusing to back a U.N. resolution on military action in Libya.
Between 2010 and 2012, the FDP was plagued by infighting and found itself ejected from six of Germany's 16 regional governments. According to some opinion polls, its nationwide support sank as low as 1 percent.
"A year ago, half a year ago, I didn't believe we would make it back into parliament, let alone the government," said Dieter Thiele, a retired physicist and grass roots FDP member who attended a rally last week in the eastern German city of Halle. "Now the mood has turned completely, and people are looking at us differently."
One reason for the turnaround is Roesler, who was parachuted into the party chairmanship at the tender age of 38, when Westerwelle's popularity was at rock bottom. He also became economy minister and vice-chancellor to Merkel.
He is one of Germany's most unlikely politicians.
Born in South Vietnam in 1973, as the Americans were winding down their involvement in the war there, he spent the first months of his life in an orphanage run by Roman Catholic nuns, before being adopted by a German couple.
His adoptive father had heard about all the abandoned children in Vietnam while training as an army helicopter pilot in the United States and was moved to adopt a baby himself.
When he and his wife split a few years later, he raised his son alone, placing him before the mirror one day to explain why he looked different from other children.
Roesler says he is German and feels German. He has not tried to trace his origins in Vietnam, though it is something he is often asked about, including by President Barack Obama on a trip to the United States.
"If I were to look, it would create the impression I am lacking something. I have never lacked anything," he said in a 2012 interview. "Germany is my home, Vietnam a part of my life I don't remember." He doesn't even know his real birth date.
Roesler praises Germany for the opportunities it offers those of foreign background, though he has encountered prejudice.
Earlier this year, when the FDP was still languishing in the polls, one of his party colleagues openly questioned whether German society was ready to accept someone who looked Asian in a position of power. In some areas of Germany, notably in the former East, he has been the target of racism, referred to as a "Jap" or "Chinaman", according to party colleagues.
In the lows of 2012, even some major media outlets appeared to resort to stereotype, painting him as a polite, earnest guy who wasn't ready for the rough and tumble of Berlin politics.
That narrative began to change last year when Roesler openly challenged Merkel over her choice for the ceremonial post of German president and won.
Then came the showdown at FDP headquarters in Berlin on January 21, a day after the FDP defied expectations and won a robust 9.9 percent of the vote in the key state of Lower Saxony.
At that meeting, Roesler shocked the party leadership by offering to step down in favor of Rainer Bruederle, a 68-year-old FDP veteran and the favored choice of FDP rebels to lead the party into the election.
A flustered Bruederle declined, and a deal was struck; Roesler would stay on as party leader, while Bruederle would be the face of the FDP's election campaign.
Katja Raab, a local FDP politician in Halle, said the duo at the top of the party allowed it to broaden its appeal before the vote: "We have Roesler's considered, academic approach, and we have the swaggering speeches from Bruederle."
Germans brand the FDP a party of the affluent, of dentists and tax advisers. Its election manifesto promises no tax rises and an end to the unpopular solidarity tax for troubled regions in eastern Germany.
"Only with us", reads its slogan, playing on the fears some Germans have about voting out a center-right government that has steered a steady course through the euro crisis.
"The mood is great. Better than at any point in the last four years, I'd say," Roesler told foreign correspondents in Berlin earlier this month. "People are listening to us, they want to know our opinions, and the whole party is very optimistic."
(Editing by Noah Barkin and Will Waterman)