Complex sentence: A regained first place from a declining People's Party (PP--A), which suffered from voters' anger at Mariano Rajoy's government management of the economic crisis and the corruption scandals affecting the party nationwide and scored its worst result since 1990.
Split into simpler sentences: A regained first place from a declining People's Party (PP--A). Suffering from voters' anger at Mariano Rajoy's national government management of the economic crisis and the corruption scandals affecting the party nationwide, the PP scored its worst result since 1990.