[1] Starting in 2002, Arce began a career in public service, serving as deputy prosecutor for controlled substances until 2005, when she joined the Cercado Province as its chief legal advisor.

In 2006, she joined the administration of Mario Cossío [es], Tarija's first popularly elected prefect, serving as legal director of the Departmental Road Service until 2008.

[8] In parliament, Arce accompanied Oliva during his four terms on the lower chamber's Energy and Hydrocarbons Committee between 2010 and 2014, in addition to spending a few months on the Planning, Economic Policy, and Finance Commission in her final year.

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.

Even as she exercised leadership over a key parliamentary post in the field of women's rights,[17] Arce often found herself contending with machista currents within her own caucus, an issue that ultimately led to her estrangement from the opposition alliance.

[18] These internal divisions culminated in 2016 when Arce refused to chair a 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.