In German terms, Angela Merkel was already on the ropes, politically speaking, before she learned Tuesday she would be facing a new challenger this September in Martin Schulz, the former president of the European Parliament.
The December terror attack on a Berlin Christmas market, which killed 12 people and injured scores, had damaged Ms. Merkel's bid for a fourth term in office, which would make her the longest-serving chancellor, surpassing Helmut Kohl.
But there were other clouds on Ms. Merkel's political radar. The economy, long her strongest suit, had begun to sputter, with inflation creeping up last month above 2 percent annually, a taboo in fiscally conservative Germany.
Mr. Schulz needs to knit together an improbable coalition -- most likely of the Social Democrats, the Greens and the centrist Free Democrats -- to take the Chancellory in Berlin.
Her own inevitability has been seriously challenged by her decision to let in more than 1 million Syrian and Iraqi refugees, which while a great humanitarian gesture has caused friction across German society, especially in her own Christian Democratic Party.
Not to mention the relentless rise of the Alternative for Germany, an upstart, anti-immigrant, euro-skeptic party that has combined shrewd public relations and Donald Trump doses of bravado to peel off voters, including from her own party.
Nationally, the AfD is polling at 14 percent this week, according to INSA, but its support, as in the cases of Brexit and Mr. Trump, may be understated.
The one advantage Ms. Merkel had held until midday Tuesday was the relative weakness of her strongest opponent -- Sigmar Gabriel, her vice chancellor in a CDU-led "grand'' coalition that appears fatigued and without ideas at a time when Europe and the United States are turning their backs on Germany.
Mr. Gabriel, who stepped down as SPD chancellor candidate citing his own unpopularity, was controversial among the German mainstream, who viewed him as an opportunist, and in his own party, which didn't like his centrist ways.
By leaving the political stage -- he will become foreign minister, replacing Frank-Walter Steinmeier, who is taking the ceremonial office of president -- Mr. Gabriel clears the way for Mr. Schulz, an improbable challenger to Ms. Merkel but perhaps the one man who can thwart her ambitions.
Mr. Schulz, although a career politician, is a relative unknown in Germany, having spent most of his career in European politics in Brussels. He is perhaps most well-known internationally, if at all, for getting into a nasty verbal exchange over corruption allegations in 2003 with Italy's then-Prime Minister Silvio Berlusconi on the floor of the European Parliament.
Challenged by Mr. Schulz on the allegations, Mr. Berlusconi responded with a joke about Nazis, marking a low point in European debate.
But the incident revealed tenacity and an appetite for conflict, a core characteristic of Mr. Schulz, 61, who grew up in a small town called Hehlrath near the Dutch and Belgian borders, one of five children of a policeman.
A trained bookseller, Mr. Schulz became involved in Social Democratic politics at an early age, and has been a key member of his party's top leadership since 1999. He is a passionate defender of Europe and has proven adept at leading delicate diplomatic missions, such as his visit to Turkish President Recep Tayyip Erdogan after the aborted coup last year, and to Iranian President Hassan Rohani after the West signed the nuclear agreement in 2015.
As the likely challenger to Ms. Merkel, Mr. Schulz will probably be an aggressive foe, attacking her over a haughty leadership style that has largely isolated Germany from its neighbors in Europe on issues such as the refugees.
With Mr. Gabriel gone, and Mr. Schulz probably in -- the SPD will meet to choose a nominee on Sunday -- Ms. Merkel's chances of taking a fourth term are bound to decline.
How much they fall, however, is the big question.
Mr. Schulz needs to knit together an improbable, fragile political coalition -- most likely one binding the Social Democrats, the Greens and the centrist Free Democrats -- to take the chancellery in Berlin.
At this point, that's probably a long shot.
Working against him are his own low profile -- he's a political unknown in his own country. On some big issues, such as the refugees, he may be closer to Ms. Merkel's position than he wants to admit. He also comes from a region near Aachen not known for producing German chancellors.
What ironically may be his strongest suit is his timing. Should -- God forbid -- more terror attacks hit Germany, Ms. Merkel's popularity will immediately plunge, and the biggest beneficiary could be a political prodigal son whose best decision was to return home at the right time, in just the right moment.