Complex sentence: Azofeifa was one of the main founders of social democracy, most notably, one of the founders of the national liberation party, until in 1989 he founded the progress party, for which he was running for president of Costa Rica.
Split into simpler sentences: Azofeifa was one of the main founders of social democracy, most notably, one of the founders of the national liberation party. In 1989, he founded the progress party, for which he was running for president of Costa Rica.