Do you need a passport to cross into Ensenada Mexico from San Diego into the Mexico at the gates to cross over.

Please check usa regulations

From what I can find online: You will need one of these documents: 1) US valid passport 2) Trusted Travel Program Card (NEXUS, SENTRI, Global Entry 3) Enhanced Driver's License. A passport is always the safest option. Good luck! And happy travels.

You need a passport for any international flight