Many existing explanations of electoral volatility have been tested at the country level, but they are largely untested at the individual party level. This study reexamines theories of electoral volatility through the use of multilevel models on party‐level data in the lower house elections of 18 Latin American countries from 1978 to 2012. Testing hypotheses at different levels, it finds that irregular institutional alteration increases electoral volatility for all the parties in a country, but the effect is more significant for the presidential party. At the party level, the results show that while a party that is more ideologically distinctive than other parties tends to experience lower electoral volatility, party age is not a statistically significant factor for explaining party volatility.