The presidential election was won by Andrés Manuel López Obrador of the National Regeneration Movement (MORENA) running as the candidate of the Juntos Haremos Historia, who secured a landslide margin of almost 31 points.

The elections also marked the first time that a coalition of political parties (excluding the PRI) supporting a single presidential candidate achieved majorities in the Senate and Chamber of Deputies.

The elections represented the PRI's greatest electoral setback and the worst for a sitting administration since universal male suffrage was implemented in 1917.

[10][11][12][13][14] On 5 September, the electoral alliance was officially registered with the INE as Frente Ciudadano por México (Citizen Front for Mexico).

[15][16] The former first lady Margarita Zavala submitted her resignation from the PAN on 6 October, after being a member for 33 years, and registered as an independent candidate six days later.

[24][25] Due to the circumstances of Meade's candidacy, critics compared his selection to the PRI's historical practice of dedazo ("tap of the finger"), where presidents hand-picked their successor.

Margarita Zavala, a lawyer, former deputy and wife of former president Felipe Calderón, had originally intended to run as the PAN nominee; however, on 6 October, she left the party and launched an independent bid.

Explaining her decision, she said that the formation of Por México al Frente meant there would be no internal PAN selection, denying her a chance to be a candidate.

A campaign described as "Red Scare-like" was used by the PRI and PAN candidates to convince voters that a López Obrador victory would turn Mexico into "another Venezuela".

It later surfaced that the woman, whose name is Carmen Martilez, is an actress who previously had uploaded a video in which she asked for street vendors to be "exterminated".

[45][46] Later in January, citizens across the country received phone calls originating in the city of Puebla, in which a recorded message warned them not to vote for López Obrador because he supposedly agreed to sell Mexico's oil to "the Russians".

During the investigation, Santiago Nieto, the ex-chief of FEPADE (the prosecutor's office that focuses on electoral violations) was controversially removed from his job in October 2017, coincidentally right after starting an investigation regarding illicit campaign money from the 2012 presidential campaign that allegedly was received by Peña Nieto and by the future president of Pemex, Emilio Lozoya, from the Brazilian conglomerate Odebrecht.

He received menacing phone messages stating: "Death follows you" and "Words of advice: stay out of Trouble", and as a consequence, he feared for the safety of his, and his family's lives.

[71] López Obrador said that failure to take action against Duarte was one of the main reasons why Mexicans had lost their faith in the PRI, saying the few ex-governors that were declared criminals were only to a pretense of concern.

Citizens on social media mocked the idea as absurd and impossible to develop, comparing it to writing letters to Santa Claus or just plainly asking for miracles.

[84] López Obrador promised to end the gasolinazos by building two new fuel refineries, which would allow more petroleum to be processed into gasoline domestically, thus lowering the price by not outsourcing the refining to other countries.

[86] On 26 January, López Obrador accused the International Monetary Fund of being an accomplice to corruption in Mexican politics and claimed that its policies are in part responsible for poverty, unemployment, and violence in the country.

[89] Rodríguez Calderón later proposed to bring back the death penalty (currently constitutionally abolished in Mexico and enforced for the last time in 1961) for drug traffickers, hijackers, infanticides and serial killers.

The statement was widely believed to be a reference to López Obrador, the leftist, frontrunner candidate, and created controversy in Mexico, as it seemed to be an attempt to influence the election against him.

[97][98][99] In December 2017, US National Security Advisor H. R. McMaster claimed that Russia had launched a campaign to "influence Mexico’s 2018 presidential election and stir up division", without defining the methods of the supposed meddling, or indicating which would be the candidate favored by the Kremlin.

[101] López Obrador responded that Ochoa's declarations are part of a smear campaign against him,[43] and later posted a video via social media, where he joked about the claims and called himself "Andres Manuelovich".

[45][46] Guatemalan right-wing commentator Gloria Álvarez embarked on a tour through Mexico, calling López Obrador a "dangerous populist" and urging citizens not to vote for him.

[102][103] US Senators Bob Menendez and Marco Rubio asked US Secretary of State Rex Tillerson to "fight Russian meddling" in the Mexican elections.

[105] Dr. Tony Payan, director of the Mexico Center at Rice University noted that there was no evidence of actual Russian tampering in the Mexican electoral process, and considered the accusations "absurd" given that the Trump administration "will not admit Russia interfered in the US election".

Bloomberg's article also suggested Meade could be receiving unfair help from the over-budget amounts of money spent on publicity by incumbent president Enrique Peña Nieto.

[108] During 2017, the PRI had faced allegations of electoral fraud concerning the election of Peña Nieto's cousin Alfredo del Mazo Maza as Governor of the state of Mexico.

Despite the official vote results given by the INE (Electoral National Institute) giving the win to del Mazo, the election was marred by irregularities including reports of vote-buying,[109] spending beyond legal campaign finance limits,[110] and electoral counts that gave del Mazo extra votes that awarded the election to him.

[111] In November 2017, left-wing magazine Proceso published an article accusing the PRI of breaking at least 16 state laws during the elections, which were denounced 619 times.

Around 30 minutes after polls closed in the country's north-west, José Antonio Meade, speaking at a news conference from PRI headquarters, conceded defeat and wished López Obrador "every success".

[113][114] Ricardo Anaya also conceded defeat within an hour of the polls closing,[115][116] and independent candidate Jaime Rodríguez Calderón recognized López Obrador's victory shortly afterward.