The insurgency was a serious hit on the image that the Government wanted to portray of a developed, advanced country, and it highlighted the negative effects of the neoliberal reforms enacted by the Salinas administration.

On the other hand, the left-wing Partido de la Revolucion Democratica (PRD), while building a wide social base, had failed to win any state governorship, which its leaders blamed on repression and electoral fraud by the PRI-controlled federal government.

Outgoing President Carlos Salinas de Gortari chose his Secretary of Social Development, Luis Donaldo Colosio, to be the PRI presidential candidate.

Salinas' choice sparked a brief internal conflict in the government, as Manuel Camacho Solís, who was then Mayor of Mexico City, had expected himself to be the PRI candidate, and quit his position in protest.

At the same time, Camacho's popularity was rising due to his role as mediator in the Zapatista conflict, and it was rumoured that he might replace Colosio as the presidential candidate.

On 6 March 1994, the anniversary of the PRI's founding, Colosio broke with Salinas in a controversial-but-popular speech in front of the Monumento a la Revolución in Mexico City.

At 5:05 PM PST on 23 March, at a campaign rally in Lomas Taurinas, a poor neighborhood of Tijuana, Colosio was shot in the head with a .38 Special by Mario Aburto Martínez at a distance of a few centimeters.

The authorities were criticized for their handling of Aburto, unusual for a detained suspect, having been shaved, bathed, and given a prison haircut before showing him to the media, which started rumors about whether a man who looked so different from the one arrested was really the murderer.

President Salinas declared three days of national mourning after Colosio's death, while all the opposition candidates lamented the assassination and called for an end to political violence.

It was speculated that Salinas wished to perpetuate his power as Plutarco Elías Calles had in the wake of the 1928 assassination of president-elect Alvaro Obregón, controlling successor presidents.

[5] A phone survey carried out by the Oficina de la Presidencia de la República Mexicana after the debate shows the widespread perception of Cevallos' victory in the debate, as well as Zedillo's lackluster performance and the appalling reception of Cárdenas' performance: However, in the aftermath of the debate, Fernández de Cevallos seemed to decrease his media presence, and Zedillo continued in the first place at the polls; on the other hand, the polls also indicated that Zedillo might win with less than 50% of the popular vote, something unprecedented for a PRI candidate (notwithstanding previous controversial elections in which the PRI was accused of fraud).

[12] Subsequent political and electoral reforms sought to provide clear rules for campaign financing, as well as less unequal access to the mass media for the opposition parties.