MEXICO CITY — Wielding the power and resources of government, Mexico’s ruling Institutional Revolutionary Party has used some of the nation’s most important institutions in an attempt to change the course of next month’s presidential election, according to independent election observers and former party officials.

The nation’s attorney general, who is appointed by the president, has publicly accused one of the main opposition candidates of serious crimes without offering much evidence. Similarly, decisions by a special court overseeing the election, which was appointed by a PRI-dominated congress, have been roundly criticized.

Hardball tactics are nothing new in Mexican politics, but the PRI’s abuse of state institutions are a staggering escalation for a party in power.

Early last year, facing abysmal poll numbers and a strong opponent in the presidential race, the party was approached by the now-defunct firm Cambridge Analytica. It offered to help the PRI win, just as it said it had done for President Trump, according to a 57-page proposal the company drafted that was obtained by The New York Times.