Starting in the late 1990s, she began rising through the ranks of northern Potosí's trade syndicates, capping off her union career as a member of the Chayanta Regional Women's Center.

Emeliana Aiza was born on 10 May 1980 in Huayraña, a small Quechua community situated in the Ocurí Municipality, part of the Chayanta Province of northern Potosí,[1] one of the poorest and least economically developed regions of the country.

[2] The eldest of three sisters, Aiza spent a large part of her early life as head of household, a situation brought about by the death of both her parents, which left her orphaned by the age of 8.

[4] As a product of its close alliance with the peasant movement, the MAS granted rural trade syndicates ample autonomy to select their own candidates in single-member constituencies.

In northern Potosí, where traditional mechanisms of choosing leaders remained common practice, the designation adhered to the principle of rotation: in 2002, the candidate had been from Pocoata [es], so for 2005, the unions instead opted for Severo Pacaja of Ravelo, accompanied by Aiza of Ocurí as his substitute.

Although disadvantaged by a bottom placement on the party's slate of candidates, she won nonetheless, owing to Evo Morales's near-eighty-percent victory in Potosí, which garnered the MAS an almost clean sweep of the department's parliamentary delegation.

In 2004, in representation of a regional workers' federation, she participated in the first-ever Leadership for Transformation Program, a political education course sponsored by the CAF – Development Bank and International IDEA.