As deputy leader, she helped lead the Center Party to a 25 percent showing in the 1973 election, and after the center-right victory three years later, Karin Söder became Sweden’s first woman foreign minister.
After the 1979 election she was named as Social Welfare Minister where she attracted much criticism for her decision to close the monopoly state liquor stores on Saturdays, a move that was reversed in 2000. After Thorbjörn Fälldin left the Center Party leadership, in 1986 Karin Söder was chosen as his successor, the first woman to lead a Swedish political party.
She was forced to relinquish the position after a year because of a serious illness. Recovering, she returned to public life, including the presidency of the Swedish Save the Children Organization.
Agneta Dreber was active in Stockholm politics during the 1980s, and was one of the founders of the Stockholm Party. She told Radio Sweden that Söder "was really a very good example and a model for other women," and that from a feminist's point of view, she had a great deal of meaning.
"But she wasn't actually talking about it, she took it very naturally. She had a status and position that no one could question because she was extremely qualified. I think that had an importance to the equality issue in Sweden," Dreber said.
According to Dreber, "there had been prejudice against women in Sweden for a very long time. There were two women before Karin Söder who could have been foreign minister: Inga Thorsson and Alva Myrdal. They were both extremely well-qualified and I think in today's government they would have been foreign ministers."
In a press release, Swedish Prime Minister Stefan Löfven writes:
“It sad news that Karin Söder has passed away. As Sweden’s first woman foreign minister and party leader, she broke new ground and inspired. She was also an important voice for disarmament and peace in the world. Karin Söder’s political accomplishments are worth respect and admiration. A pioneer in Swedish politics has left us.”