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An ally of Chancellor Angela Merkel who is running to succeed her as leader of Germany's main center-right party said Wednesday that an era is ending with Merkel's departure but her legacy can't be reversed.

Annegret Kramp-Karrenbauer, a former state governor and now the general secretary of Merkel's Christian Democratic Union, also promoted her own service to the party and years of government experience as she presented her candidacy.

Merkel announced last week she will give up the CDU leadership after 18 years in December but plans to remain chancellor, a job that she has held for 13 years, until the next election.

Kramp-Karrenbauer, 56, is regarded as one of the favorites to succeed Merkel, along with a onetime rival of the chancellor, former parliamentary leader Friedrich Merz, who is seeking a comeback after a decade away from frontline politics.

Merz, 62, stands for a more conservative approach than Merkel's centrist line, as does the third high-profile candidate, 38-year-old Health Minister Jens Spahn.

Kramp-Karrenbauer sought to portray herself as someone who can deliver renewal to a party sagging in polls but also a reassuring measure of continuity.

"With the party leader's decision, this era is ending, and such an era can't be continued indefinitely — but it also can't be reversed," she said at a news conference in Berlin, adding that "you always, in both positive and negative ways, stand on the shoulders of your successor."

"It is time to open a new chapter with new issues, with a new style, to achieve new strength," she said.

Kramp-Karrenbauer's pitch dwelled heavily on her nearly 18 years in government in western Saarland state, where she was the first woman to serve as a German state's interior minister and more recently a popular governor.

She noted that she gave up that job in February to become the party's general secretary, putting herself "at the service of the CDU," and has spent recent months listening closely to members. She said she has "particular experience in how to win majorities ... and how to defend them."

Kramp-Karrenbauer said that, over recent years, Germans' feeling of security and trust in a strong state have diminished.

But she warned against reheating arguments over the rights and wrongs of Merkel's decision in 2015 to allow in large numbers of migrants. Rival Spahn has emphasized concerns about migration.

People "don't expect of us that we spend another three years arguing retrospectively about what was right, less right and wrong in 2015," she said. "You don't win people's confidence in security with harsh tones, with shrill demands."

Many observers question whether Merkel can realistically stay much longer as chancellor after a new CDU leader is elected. The next election isn't due until 2021 but Merkel's coalition with the center-left Social Democrats is in poor shape.

"She is the elected chancellor ... and as long as she has a majority in parliament, she will certainly remain," Kramp-Karrenbauer said.