In the immediate aftermath of the coup, the various sectors within the UCD closed ranks briefly around their new prime minister, Calvo Sotelo, but internal cleavages prevented the formation of a coherent centrist party. Clashes between the moderate and the rightist elements within the UCD, particularly over the divorce bill, resulted in resignations of dissenting groups and the formation of new splinter parties and coalitions. These developments in turn led to a series of election defeats in 1981 and 1982, and by the time a general election was called in August for October 1982, the UCD's representation in the Cortes was down by one-third.

As the UCD continued to disintegrate, the PSOE gained strength it was considered more likely than the increasingly conservative UCD to bring about the sweeping social and economic reforms that the Spanish people desired. Moreover, party leader Gonzalez had been successful in his efforts to direct the PSOE toward a more centrist-left position, as seen in his successful persuasion of PSOE delegates in 1979 to drop the term "Marxist" from the party's definition of itself. The PSOE was thereby able to project an image of greater moderation and reliability, and it became a viable governmental alternative. The PSOE also benefited from the decline of the PCE. The heavy-handed management style of PCE leader Santiago Carrillo had aggravated the dissension in the party over whether to follow a more revolutionary line or to adopt more moderate policies. As was the case with the UCD, internecine disputes within the PCE resulted in defections from the party. With the PCE apparently on the point of collapse, the PSOE became the only feasible option for left-wing voters.

When Spaniards went to the polls in record numbers in October 1982, they gave a sweeping victory to the PSOE, which received the largest plurality (48.4 percent) in the post-1977 period. The party enlarged its share of the 350 seats in the Chamber of Deputies to 202, while the UCD, with only 6.8 percent of the vote, won only 11 seats. The conservative AP took on the role of opposition party (see Political Developments, 1982-88 , ch. 4). The most significant implication of the October elections for the future of democracy in Spain was the transfer of power from one party to another without military intervention or bloodshed. The transition to democracy appeared to be complete.

Data as of December 1988