A comparison of the two time series, taking into account the fact that both parties have had several leaders along the last 23 years, allows the following remarks. In the first place, the leader of PSOE has generally been better rated than the leader of PP, confirming the widespread idea that the Spanish electorate is more leftist than rightist (or more specifically, that it is predominantly in the center-left). In fact, the leader of PP (Aznar) was better rated than the leader of PSOE (Borrell and Almunia) only from October 1998 to October 2000.
Whenever a party has changed its leader, rating of the new one has generally been high, as when Hernández Mancha replaced Fraga in 1986, when Fraga replaced Hernández Mancha in 1989, or when Zapatero replaced Chaves and Almunia in October 2000. That did not happened, however, when Almunia replaced González after the 1996 elections. What seems to be true is that the rating of the leader of PP has been closer to that of the leader of PSOE since Aznar became the leader of PP in 1989. Other important facts that must be underlined are the strong fall of Felipe González’s rating between the 1993 and the 1996 elections (as a consequence of corruption scandals and the GAL issue, especially during the 1994 spring, that led to the defeat of PSOE in the 1996 elections). And certainly the significant fall of Aznar’s rating in 2003 as a consequence of his implication in the Iraq conflict.
What is really remarkable and surprising in these two time series, however, is the persistent fall in the rating of the leaders of both parties since the 2004 elections. Aznar enjoyed an increase in his rating during his first legislature (1996-2000) though it fell very rapidly during the second. But the rating of Rodríguez Zapatero has shown an unequivocal trend to decrease since his first legislature and through the second. Both he and Rajoy are at present in the lowest levels of ratings obtained by their precedent leaders since 1986. And both are in very low and similar rating levels at present.