Overhang seat

Overhang typically results from the winner-take-all tendency of single-member districts, or if the geographic distribution of parties allows one to win many seats with few votes.

As with the previous system in Bavaria, overhanging constituency winners are excluded in order of lowest vote share.

This, along with the rise of Alliance '90/The Greens, served to depress the party-list vote shares, creating more overhang seats than in prior elections.

In the 1994 German federal election, the re-elected Kohl government supported by a "black-yellow" coalition (CDU/CSU and FDP) achieved a relatively slim majority of 341 out of 672 seats to the opposition's (SPD, Alliance 90/The Greens, PDS) 331 seats at the opening session.

[13] The problem thus turning from a theoretical consideration to a real issue, the German Constitutional Court as early as 1997 ruled that a "substantial number" of overhang mandates which weren't equalized through leveling seats were unconstitutional.

Der Spiegel published an article in the intervening time outlining how more votes for the CDU could lead to them losing an overhang seat, and thus narrowing their plurality in the close election.

[16] This led to another ruling by the German Constitutional Court in 2008 which ruled that the existing federal electoral law was unconstitutional in part as it violated the principle of one person one vote and produced an overly opaque relationship between the numbers of votes cast and seats in parliament.

The electoral reform passed with the votes of the governing "black-yellow" coalition in late 2011 (a few weeks after the deadline set in 2008) - and without consulting the opposition parties - was again ruled unconstitutional by the Constitutional Court.

[22][23] As the Bundestag thus lacked a constitutional electoral mechanism[24] and the 2013 German federal election was coming up, the government agreed to negotiations with the opposition parties, leading to a new electoral law being passed in early 2013 with broad support from all parties in the Bundestag except Die Linke.

On the state level, an unclear wording in the state electoral law of Schleswig-Holstein led to different possible assignments of leveling seats to equalize the overhang seats ultimately resulting in the 2009 Schleswig-Holstein state election giving a majority of seats to the Peter Harry Carstensen led "black-yellow" coalition, despite them having won a lower share of the vote than the SPD, Greens, Left, SSW opposition.

Following a suit before the State Constitutional Court brought by opposition parties,[26] it was ruled that the electoral law in its then current interpretation did indeed violate the state constitution but that the Landtag was to keep its composition until a new electoral law could be passed (which happened in 2011) after which new elections would be scheduled with enough time for campaigns setting the next election for 2012, two years earlier than if the Landtag had served its full five year term.

If a party wins at least three constituency seats, it is granted full proportional representation as if it passed the 5% electoral threshold, even if it did not.

The rule allowing any party winning three constituency seats to receive full proportional representation was originally also abolished.

The Federal Constitutional Court, however, decided that a 5% electoral threshold with no exceptions was unconstitutional and the rule was restored on an interim basis for the 2025 election.