He did some consulting and worked in the private sector before joining the local chapter of the National Action Party in 1983 and becoming its first member to ever win the mayorship of Juárez, Chihuahua.

He ran for governor in 1986 and lost against the PRI candidate, Fernando Baeza Meléndez, in one of the most controversial elections in the state's recent history[citation needed].

Barrio refused for years to mount an inquiry, and suggested the attacks were not surprising because the victims walked in dark places at night and wore provocative clothing.

During his tenure as governor, the State of Chihuahua placed first in the country in anti-corruption and good governance, according to the annual review conducted by the prestigious Monterrey Technological Institute of Higher Studies (ITESM).

On February 24, 2005, he expressed interest in becoming the PAN presidential candidate and campaigned for a few months before quitting on July 7, arguing partisan favoritism towards the former minister of the interior, Santiago Creel.