to who they were than how many of them there were. If we look strictly at the number of switchers, their impact was limited. Switchers added 1.5% to the CDU’s parliamentary size in the first legislature (for a total of 36% of seats), 2.0% in the second (51.9%) and 2.4% in the third (56.7%).6 Such switchers did not alter the overall fragmentation since they were too infrequent to offset fissions and switches from larger to smaller parties. Switchers joining the CDU/CSU mattered somewhat more in 1953-57 because they increased the CDU/CSU a parliamentary majority and thus lessened its dependence on the other parties making up the coalition government.
Switching Effect on Minor Parties: If the switchers joining the CDU/CSU were too few to reduce fragmentation, they were too important to be inconsequential for the parties from which they exited. The CDU/CSU accepted five of the twelve BP deputies in 1952, nine of the twenty seven GB/BHE deputies in 1955 and eleven out of seventeen DP deputies in 1960. These party switches received significant media attention and thus further undermined public confidence in electoral viability of the switchers’ old parties. Moreover, these parties’ winning prospects were further diminished by the fact that most switchers were senior party members with considerable public reputations, extensive contacts with interest groups and a lot of political experience. Losing the these assets undermined the electioneering effectiveness of the switchers’ old parties.
These switches to the CDU/CSU all followed a similar pattern. They usually began with an internal crisis in the switchers’ old party. The trigger for such a crisis was either a disappointing election result or the concern about losing the party’s identity by cooperating so closely with the CDU/CSU. In response to such a crisis, a majority faction usually responded by advocating the departure from the CDU/CSU-led federal coalition government, joining a state-level coalition government with the SPD or seeking a merger with another minor party. These proposals sought either to ideologically differentiate oneself from CDU/CSU and thereby win back disgruntled voters; or, in the case of mergers, to pool votes to reduce strategic voting. After these proposals were tabled, a minority faction opposed them because its members, usually senior party members, were
6 These figures express the CDU’s net seat gains as result of switching and as such also take into account the seats it lost as a result of its deputies switching to minor parties.