Unlike the ideologically based MPLA, the UPA and other Bakongo nationalist movements appealed directly to the Bakongo ethnic group and the heritage of the old Kongo kingdom.  Though Holden Roberto had ambitions of making the UPA/FNLA a nation-wide movement with broad-based support, it remained for most of its history an organization dominated by Bakongos, and was responsible for numerous acts of violence against mestiços, assimilados, whites, and non-Bakongo Africans, particularly the Ovimbundu who worked on the coffee plantations of the north.  Its reputation for violence and the lack of discipline among its ranks led many to distrust the FNLA, and greatly decreased its effectiveness.  Infighting plagued the organization throughout its history as well. 