Mexican President Enrique Peña Nieto plagiarized parts of his thesis in 1991 for his Panamerican University law degree, according to reporting by celebrated Mexican journalist Carmen Aristegui  and her team.
The independent news site Sopitas explained the findings, which were published on Aristegui's website  on August 21, 2016:
El equipo de investigaciones de Carmen Aristegui encontró que la tesis de EPN tiene 197 párrafos que fueron plagiados de un total de 682. El plagio fue textual, no hubo entrecomillado ni cita alguna.
Carmen Aristegui's investigative team found that out of 682 paragraphs, Peña Nieto plagiarized 197. The plagiarism was exact. There were no quotations or citations at all.
The Spanish-language video below summarizes a piece published by Aristegui's team titled “Peña Nieto, from Plagiarizer to President”:
Enrique Peña Nieto plagió párrafos textuales de una obra escrita por el expresidente Miguel de la Madrid, sin hacer referencia a él ni citarlo en la bibliografía. También se atribuyó palabras de al menos diez autores, entre ellos, el historiador Enrique Krauze, y los doctores en derecho Diego Valadés y Jorge Carpizo.
Enrique Peña Nieto plagiarized exact quotes from a piece by ex-President Miguel de la Madrid, failing to reference the author or citing him in the bibliography. Work by at least 10 other authors were also plagiarized, among them the historian Enrique Krauze and Doctor's of Law Diego Valadés and Jorge Carpizo.
Panamerican University, Peña's alma mater, is a private university for high-income families and privileged individuals and has a relationship with the Roman Catholic institution Opus Dei . According to a report by financial news site Forbes, as a result of the Aristegui report , Panamerican University will review Peña's thesis.
On Twitter, a user called México Denuncia reminded readers that presidents from other countries who saw themselves embroiled in similar scandals have resigned from their posts:
The Hungarian president resigned after reports confirmed that he had plagiarized his thesis
Norma Sanchez quoted commentary  on the left-leaning news site Horizontal:
— norma sanchez (@normasanchez7) August 24, 2016 
Involuntary plagiarism doesn't exist: Enrique Peña Nieto's plagiarized thesis reveals a lot about his ethics as a politician.
David G. Paz Marín argued the issue revealed two things:
Con la tesis de EPN, saltan dos cosas: la falta de acusiocidad del Presidente y el rigor académico de la dicha Universidad Panamericana.
— David G. Paz Marín (@DavidGPazMarn) August 23, 2016 
Peña Nieto's thesis exposes two things: A lack of diligence on the part of the president and a lack of academic rigor on the part of Panamerican University.
José Luis Huerta pointed out that there are more aspects to consider:
Quién fue el asesor de tesis de EPN? Qué puede decir la Universidad Panamericana al respecto del plagio?. Esa podría ser la nota Aristegui.
— José Luis Huerta (@JlhuertaD) August 23, 2016 
Who was Peña Nieto's thesis adviser? What does Panamerican University have to say about his plagiarism? This could be a piece by Aristegui.
In the past, Aristegui and her team were responsible for exposing the apparent conflict of interest known as “White House” in which a business consortium  with public contracts sold or handed over a luxury house to Peña's wife. Recently, the president apologized  for the case in a public announcement:
No obstante que me conduje con apego a la ley, aceptó y reconozco que cometí un error. Este error afectó a mi familia, lastimó la investidura presidencial y dañó la confianza de la sociedad. En carne propia sentí la indignación de los mexicanos, por eso, con toda humildad, les pido perdón.
Even though I am driven by the law, I accept and recognize that I made a mistake. This mistake affected my family, hurt the presidential investiture and damaged the public's trust. I have felt, first hand, indignation from the Mexican people and for this, with complete humility, I ask for forgiveness.
However, nobody in his cabinet or from his family took on any responsibility for the issue. Until now, Peña Nieto has not made any statements about Aristegui's recent accusation of plagiarism.
Additionally, in February of this year, Aristegui reveled supposed ecclesiastic irregularities in relation to the president's second wedding .
It is important to note that not everybody is happy with the way that the well-known journalist has dealt with the government in her reports.
On the website SDP Noticias, which is an independent news source with the most site visits in the country according to comScore , Federico Arreola minimized the news  published by Aristegui with the following comment:
Si acaso, como mencionaron algunos tuiteros, lo único que demuestra Carmen Aristegui es que EPN leyó mucho más de tres libros para hacer su tesis de licenciatura.
Ojalá la respetada señora Aristegui se olvide de sus obsesiones contra Peña Nieto y vuelva ya a la seriedad periodística.
As mentioned by some Twitter users, the only thing that Carmen Aristegui has proven, if at all, is that Peña Nieto read more than three books to write his bachelor degree's thesis.
Hopefully, the respected Mrs. Aristegui will forget her obsession with Peña Nieto and return to serious journalism.
Regarding the issue, Madame Déficit commented on her Twitter:
Carmen Aristegui es la periodista consentida de @lopezobrador_  y sus fanáticos seguidores. Eso no implica que todo su trabajo sea veraz
— Madame Déficit (@Alessia_mx) August 23, 2016 
Carmen Aristegui is a favored journalist of Andrés López Obrador and his fanatic followers. This does not mean that all of her work is real.
Andrés López Obrador is one of the main political opponents of the president and his party .
The user @blurred9 had this to say about Aristegui's report:
Vivimos en un país en el que la corrupción y la impunidad son una situación normal. Y un reportaje de plagio de tesis NO lo va a cambiar.
— red (@blurred9) August 22, 2016 
We live in a country where corruption and impunity are the norm. A report about plagiarism is NOT going to change this.
There has been controversy in previous administrations between Aristegui and the presidency, including an episode where Aristegui divulged that Felipe Calderón , predecessor to Peña Nieto and a member of a different political party, was an alcoholic. This was a claim that was never proven and, according to many versions of the story,  may have gotten Aristegui fired from the radio station where she worked.
The impact of Aristegui's recent report on President Peña remains to be seen, but judging from previous incidents, the president has very little to worry about.