[2][4] When the Bolivian Workers' Center—CONMERB's parent organization and the primary ally of the Movement for Socialism (MAS-IPSP)—announced its intent to form its own caucus within the Legislative Assembly, Mamani was put forward to represent the rural education sector.

[7] The MAS majority in the Chamber of Deputies formally elected Mamani on 3 November 2020, making him the first representative of the rural education sector to hold the post, a position he pledged to use to promote the passage of education-related legislation.

However, broader disputes between the MAS's La Paz caucus and representatives from other departments, who put forward Santa Cruz Deputy Jerges Mercado, allowed Mamani to emerge as a consensus candidate, securing him a second term in a tight vote for the party's nomination.

With neither La Paz's Freddy López nor Santa Cruz's Jerges Mercado willing to support the other, Mamani opted to suspend the session convened to elect a new directorate, giving the competing factions three days to reach an agreement.

[13][14][15] This strategy was most pronounced in September 2022, where, after four failed votes, Mamani approved a last-minute change in parliamentary agenda to facilitate the election of Pedro Callisaya as the country's next ombudsman, taking advantage of the absence of over thirty opposition legislators, who were on leave for various reasons.