Bavaria (Bundestag electoral district)

Members of the Bundestag for Bavaria are elected using a complex mixed-member proportional representation electoral system that has evolved over time.^[4][5]

1949 Electoral Act
The Parliamentary Council of West Germany, a constituent assembly elected by Parliaments of the eleven states of West Germany, could not agree upon the electoral law to be included in the Basic Law, the constitution of the nascent nation. The Council instead established a special committee to draft an electoral law for the first federal election. In February 1949 the Council adopted an electoral law which would establish a mixed electoral system with 50% of seats elected using the first-past-the-post system and the other 50% via federal lists, and there would no electoral threshold. The Allied-occupying authorities objected to the new electoral as they considered that the Parliamentary Council was not competent to enact electoral law and only the states could do so. The minister presidents of the states referred the issue back to the Parliamentary Council which passed another electoral law on 10 May 1949 with a two-thirds majority. The Allied military governors objected to several parts of the new law and ordered changes to be made. In response, the minister presidents promulgated an amended electoral law on 15 June 1949, the "Electoral Act for the first Bundestag and the first Federal Assembly of the Federal Republic of Germany" (Wahlgesetz zum ersten Bundestag und zur ersten Bundesversammlung der Bundesrepublik Deutschland).^[5][6] On 5 August 1949 the minister presidents promulgated an amendment to the electoral law in relation to method of calculating the seat allocation in the upper-tier electoral districts.^[7]

The amended law provided for 400 members of the Bundestag of which 78 would be elected from Bavaria.^[6][8] Each state government was to distribute the seats in their respective states with 60% of seats being allocated to constituency seats or direct mandates (Direktmandat) elected from lower-tier single-member constituencies with the remaining 40% of seats being state seats allocated to state lists (Landesliste or Landeswahlvorschlag) elected from upper-tier multi-member electoral districts.^[6][9] In the lower-tier constituencies the candidate with the most votes was elected (plurality voting).^[6][10] In order to calculate the state seats won by each party, the total seats allocated to each state, excluding constituency seats won by independents and parties that did not submit a state-list nomination, were distributed to parties using the D'Hondt method.^[7][10] Only parties that had received at least 5% of the votes in the state or had won at least one constituency seat in the state (the basic mandate clause Grundmandatsklausel) were included in this calculation.^[7][10] Then the number of constituency seats won by the party in the state were deducted to determine the number of state seats won by each party.^[7][10] If the number of constituency seats won by a party exceeded the calculated number of seats it was entitled to in the state, it was permitted to retain the overhang seats (Überhangmandat).^[7][10] Finally, the state seats won by each party were distributed amongst its candidates in the order they appeared on the state list (closed list).^[7][10]

Vacancies in constituency seats were filled by by-elections until January 1953 when an amendment to the electoral law abolished by-elections and instead vacancies were filled from the party's state list.^[6][11]

1953 Electoral Act
In July 1953 a new electoral law, the "Electoral Act for the Second Bundestag and the Federal Assembly" (Wahlgesetz zum zweiten Bundestag und zur Bundesversammlung), was enacted.^[5][12] The new law provided for 484 members of the Bundestag of which 91 would be elected from Bavaria.^[12][13] The split between constituency seats and state seats was changed from 60:40 to 50:50 as the Parliamentary Council had envisaged in 1949.^[5][12] Voters had two votes instead of one - with their first vote (Erststimme) they chose a candidate in the lower-tier constituency and with their second vote (Zweitstimme) they chose a state list in the upper-tier electoral district.^[12][14] Split-ticket voting (panachage) was permitted.^[14] The two thresholds required to compete for state seats were transferred from the state level to the national level.^[12][14] Parties representing recognised national minorities (Nationale Minderheit) were exempt from the threshold requirements.^[12]

1956 Electoral Act
The "Bundeswahlgesetz" (Federal Election Act) enacted in May 1956 was the first permanent electoral law in post-war West Germany (the 1949 and 1953 Acts were provisional and only applied to the subsequent federal election).^[15][16] In December 1956 the Act was amended in relation to size of the Bundestag following the accession of Saarland to the federal republic.^[17] The Bundestag was to have 494 members (excluding the 22 non-voting members from West Berlin) but, unlike the previous Acts, seats weren't allocated to individual states which in effect meant seats were distributed amongst participating parties based on the national vote rather than on the state vote as previously.^[16][17] The requirement to have won at least one constituency seat nationally to compete for state seats was increased to at least three constituency seats nationally.^[16][17] The 5% threshold and exemption for parties representing recognised national minorities remained as previously.^[16][17]

The calculation of the number of state seats won by each party was carried out in three stages. Firstly, the total number of Bundestag seats - excluding constituency seats won by independents, parties that did not submit a state-list nomination and parties that did not meet the threshold requirements - were allocated amongst parties that met the threshold requirements based on their national total of second votes and using the D'Hondt method.^[16][17] Secondly, the seats allocated to each party was distributed to the upper-tier electoral district level based on their state total of second votes and using the D'Hondt method.^[16][17] Finally, the constituency seats won by the party in the state were deducted to determine the number of state seats won by each party.^[16][17] Parties retained overhang seats as previously.^[16][17]

In February 1964 the Act was amended to increase the size of the Bundestag from 494 to 496.^[18]

1975 Electoral Act
A new version of the Act was enacted in September 1975 but made no changes to electoral system.^[19] The method for allocating state seats was changed from D'Hondt to the largest remainder method with Hare quota in March 1985.^[20][21]

In June 1990 the Act was amended to allow the accession of the East German states into the federal republic, increasing the size of the Bundestag from 496 to 656.^[22][23] The Federal Constitutional Court ruled in September 1990 that the 5% national threshold violated the principle of equal voting rights as political parties from East Germany needed to increase their votes by a relatively larger amount than parties from West Germany in order to meet the threshold in a unified Germany.^[24] In response, the electoral law was amended in October 1990 to have separate 5% thresholds for East and West Germany and passing either one would allow the party to compete for upper-tier electoral district seats in the whole of Germany.^[22][25] This change was transitional and only applied to the subsequent election.^[26]

1993 Electoral Act
A new version of the Act was enacted in July 1993 but made no changes to electoral system.^[27] In November 1996 the Act was amended to decrease the size of the Bundestag from 656 to 598 but this change wasn't applied until the 2002 federal election.^[22][28] The method for allocating state seats was changed from largest remainder to the Sainte-Laguë method (also known as the Schepers method) in March 2008.^[29][30]

The existence of overhang seats at state level together with seats being allocated initially at the national level led to the possibility of negative vote weight - the more second votes a party received in a state in which it had overhang seats, the fewer overall seats it would end up receiving.^[31] The Federal Constitutional Court ruled in July 1998 that this violated the princicple of equal votes enshrined in the Basic Law.^[32] In response, the Act was amended in December 2011 but in July 2012 the Constitutional Court ruled this too violated the Basic Law as it still raised the possibility of negative vote weight.^[33][34] The Act was amended again in May 2013 to meet the Constitutional Court's ruling.^[35] The main changes were that the seats were allocated initially based on second votes at the state level rather than on the national level, and the introduction levelling seats (Ausgleichsmandat) to ensure that the final overall seat allocation was proportional to the second votes.^[5] The threshold limits and the method of electing lower-tier constituency seats remained unchanged.

The calculation of the state seats won by each party was carried out in multiple, circular stages. Firstly, the total number of seats in the Bundestag (598) was distributed amongst the upper-tier electoral districts based on their population of German citizens.^[35] Secondly, the total seats allocated to each upper-tier electoral district - excluding seats won at the lower-tier constituency level by independents, parties that did not submit a state-list nomination and parties that did not meet the threshold requirements - were allocated amongst parties that met the national threshold requirements based on their total second votes in the state and using the Sainte-Laguë method.^[35] Then the number of constituency seats won by the party in the state were deducted to determine the initial allocation of state seats won by each party. Parties retained overhang seats as previously. Each party's minimum seat entitlement was the sum of the initial allocation of state seats plus the number of constituency seats won by the party, including overhang seats. Next, the ratio of second votes to minimum seat entitlement was calculated for each party. Then, each party's second votes total was divided by the lowest of these ratios to determine the final national seat allocation.^[36] The difference between the final national seat allocation and the minimum seat entitlement was the number of levelling seats.^[36] The final national allocation was then distributed to the upper-tier electoral district level based on the number of second votes received by that party in each state but ensuring that each party received at least as many seats as the number of constituency seats the party won in the state.^[35] Finally, the number of constituency seats won by the party in the state were deducted to determine the final allocation of state seats won by each party.^[35] This final allocation of state seats could be lower than the initial allocation. One new clause in the Act was that if a party received more than half of the total number of second votes received by parties that met the threshold requirements, but did not not receive more than half of the seats, additional seats were to allocated to that party, using the same top-down method as above, until it received one seat more than half of the total number of seats in the Bundestag.^[35]

The existence overhang seats plus changes in the party system in Germany meant more and more levelling seats were required to achieve proportionality.^[37] In order to mitigate this, the Act was amended in November 2020 so that any overhang seats in excess of three for a party in a state would be off-set by a commensurate reduction in the party's state seats in other states.^[37][38] At the 2021 federal election the Christian Social Union received 12 overhang mandates in Bavaria but, as it only competed in that state, its nine excess overhang seats could not be off-set by a reductions in state seats elsewhere and as result 104 levelling seats were needed to achieve proportionality.^[37] This, together with a total 34 overhang seats, took the size of the Bundestag to 736, the largest in the democratic world.^[37]

The Act was amended in June 2023 to eliminate overhang seats, and therefore the need for levelling seats.^[39][40] The size of the Bundestag was increased from 598 to 630 whilst the basic mandate clause was abolished.^[37][39] The latter change was challenged in the Constitutional Court which ruled on 30 July 2024 that the 5% threshold without any exceptions was unconstitutional and ordered the reinstatement of the basic mandate clause on an interim basis.^[41][42] The calculation of the number of state seats won by each party was similar to the process used prior to the 2013 reform, with the exception that if a party won more constituency seats in a state than it was entitled to, its constituency winners were excluded from the Bundestag in decreasing order of their first vote share.^[37][39]

Bavaria is currently divided into 47 lower-tier constituencies:^[43]