German Chancellor and leader of Germany's conservative Christian Democratic Union (CDU) Angela Merkel (C), the State Premier of the southwestern federal state of Saarland Annegret Kramp-Karrenbauer and CDU secretary-general Peter Tauber arrive at the CDU headquarters in Berlin on February 19, 2018.
Popularly known as "mini-Merkel", Ms Kramp-Karrenbauer has always been seen as the chancellor's preferred successor.
Although Tauber is seen as a close associate of Merkel's, infighting within the CDU (Christian Democratic Union) led the chancellor to designate another party stalwart to draft the party's electoral platform past year.
As the CDU's secretary-general, Kramp-Karrenbauer would follow in the footsteps of Merkel who held the position from 1998 to 2000 before becoming chancellor in 2005.
The chancellor praised Kramp-Karrenbauer, known as AKK, as someone "who has experience and knows her own mind, whose work I have valued for years". She also played a key role in Merkel's tough coalition negotiations with the centre-left Social Democrats.
Outgoing secretary general Peter Tauber is giving up the role after a period of illness.
AKK is described as a pragmatic and unpretentious politician seen as a safe choice to preserve Merkel's legacy.
A staunch Catholic and mother-of-three, AKK could also appeal to the more conservative wing of the CDU, which has accused Dr Merkel of undermining the party's traditional values.
The debacle is the latest in a series of humiliations for the SPD, and comes a day after an opinion poll found its support has fallen so low it is now in third place behind the nationalist Alternative for Germany party (AfD). Amid a menacing SPD resurgence under Martin Schulz, her triumphant re-election didn't go unnoticed, as Merkel congratulated AKK, presenting her with a bouquet of flowers.
For Schulz, the regional defeat contributed to a downward spiral that saw him lead the SPD to its worst score in decades at September's polls.
The deal is still subject to a ballot by the SPD's deeply divided base of 470,000 rank-and file members.
In 2015, she voiced her concerns that "if we open up [the definition of marriage] to become a long-term responsible partnership between two adults, then other demands can't be ruled out, such as a marriage between close relatives or between more than two people", which prompted fierce criticism from the SPD, Green Party and the German Left for comparing homosexuality with incest and polygamy.