Complex sentence: Schechter has served as principal election advisor in nearly every country in Latin America, including work for President Alvaro Uribe (his fourth Presidential client in Colombia), President Fernando Henrique Cardoso in Brazil, and President Ernesto Zedillo in Mexico.
Split into simpler sentences: Schechter has served as principal election advisor in nearly every country in Latin America. This includes work for President Alvaro Uribe (his fourth Presidential client in Colombia), President Fernando Henrique Cardoso in Brazil, and President Ernesto Zedillo in Mexico.