MEXICO CITY (AP) — With signs shouting “No to repression!” and “Down with the PRI!” the angry students who have taken the streets of Mexico with flash protests have become the most visible face of youth in this election.

They have challenged the presidential candidates to debates, urged others their age to pay attention to the campaign, and sought to fight off the return of the Institutional Revolutionary Party, which held power for 71 years until its ouster in 2000.