As of September 2023, she is also the longest serving former female minister-president of a German state (11 years, 343 days).

[1][4] She was elected to the German Bundestag in 1976,[1] representing the Rendsburg-Eckernförde district, as then the youngest member of the parliament.

[4] In the 2000 state elections, at the height of a Christian Democratic Union's donations scandal, the SPD was able to increase its share to 43.1%.

At the time, the result was also seen as marking a victory for Chancellor Gerhard Schröder, who had campaigned ardently in support of Simonis.

[7] Despite basing its campaign for the 2005 elections on Simonis' popularity, the SPD suffered a heavy defeat due to the bad economic situation and its support dropped to 38.7% (for the first time in almost twenty years behind the CDU).

In the second and third ballots the candidates received 34 votes each, while one deputy of the alliance of SPD, Greens, and SSW abstained.

[2][10] President Frank-Walter Steinmeier described her as an exceptional political personality who shaped democracy beyond Schleswig-Holstein.