Mirtha Arce

Nearing the end of her term, Arce resigned from office to contest a seat in the Chamber of Senators. She aligned herself with Samuel Doria Medina's Democratic Unity coalition, a bloc that recycled much of National Convergence's previous electoral list in a bid to guarantee a high degree of parliamentary representation. Elected in 2014 and sworn in the following January, Arce spent her first year heading the Senate's Electoral System, Human Rights, and Social Equity Committee. Even as she exercised leadership over a key parliamentary post in the field of women's rights, Arce often found herself contending with machista currents within her own caucus, an issue that ultimately led to her estrangement from the opposition alliance. The culmination of these internal divisions came in 2016 when Arce refused to chair the committee her caucus had assigned to her, opting instead to seek a position on the Senate's powerful Ethics Commission. With the supporting votes of legislators from the ruling Movement for Socialism, Arce obtained the post, beating out the candidate nominated by the rest of the Democratic Unity caucus. The following year, Arce officialized her break with the alliance with which she was elected. For the duration of her term, she operated individually, independent of the Senate's three parliamentary caucuses.

Arce developed much of her career in academia, starting out as a university professor at the UJMS and the Bolivian Catholic University's Tarija campus. She was a founding member and president of the Association of Women Lawyers and the Association of Women University Professionals, served as vice president of the Tarija Women's Civic Committee, and composed part of the directorate of the National Confederation of Women's Institutes of Bolivia. Starting in 2002, Arce began a career in public service, serving as deputy prosecutor for controlled substances until 2005, when she joined the Cercado Sub-Prefecture as its chief legal advisor. In 2006, she joined the administration of Mario Cossío, Tarija's first popularly elected prefect, serving as legal director of the Departmental Road Service until 2008.

Arce's political ideology has been described as "liberal in economics" but "conservative in morals". She was an early supporter of departmental autonomy, a political system heavily pushed by the country's lowland departments in the early 2000s. Despite her lack of party affiliation, Arce's adherence to decentralization and prominence in women's rights organizations contributed to her nomination for a seat in the Chamber of Deputies in 2009. She accompanied Adrián Oliva as his substitute, topping the National Convergence alliance's electoral list in the department. Arce's tenure in the lower chamber reflected that of many substitute parliamentarians, focusing less on legislating from the capital and more on fostering local connections in her home department.

Mirtha Natividad Arce Camacho (born 25 December 1963) is a Bolivian academic, lawyer, and politician who served as senator for Tarija from 2015 to 2020. Arce got her political start in student leadership before developing her career in the fields of academia and women's rights. She held multiple executive positions in women's rights-related organizations in Tarija, including presiding over the Association of Women Lawyers and the Association of Women University Professionals. Between 2002 and 2008, she exercised law-related public service roles at the local and departmental levels, including serving as legal director of the Departmental Road Service. In 2009, Arce was elected to the Chamber of Deputies, accompanying Adrián Oliva as his substitute from 2010 to 2014, when she resigned to contest a Senate seat. Though elected as part of the Democratic Unity coalition, Arce became estranged from the bloc partway through her term and operated independently from there on. In 2021, she contested the Tarija governorship but came in a distant fourth place.

Mirtha Arce was born on 25 December 1963 in Tarija to Rosandel Arce and Ana Camacho. Arce completed her secondary schooling at the Santa Ana School, where she served as class president. She went on to attend the Marshal Sucre Normal School as well as Juan Misael Saracho University (UJMS), where she graduated as a lawyer and pedagogue, completing two master's degrees in crime science and higher education and five postgraduate degrees in the fields of educational research and university teaching. During her time in university, Arce continued to be active in student leadership, serving for two terms as executive of the UJMS Law Student Center, becoming the first female head of said body. From there, she went on to compose part of her Local University Federation and the Bolivian University Confederation and was named executive of the Bermejo Teachers Federation.