Do I Need Passport to Cross the Border into Mexico to Drive to Ensenada from San Diego?

(from USA)

Do you need a passport to cross the border into Mexico to drive to Ensenada from San Diego?
I have 3 grandchildren that live in San Diego and I would like to take them to Ensenada for a little vacation but I am the only one with a passport.
If their father comes with me, does he need a passport too? Thanks!

----- Our answer:
If you are a U.S. citizen: YES!!!
While an ID with photo is currently accepted for land entry to Mexico, you will be required to show your passport when returning to the U.S.

U.S. citizens returning to their country by land or sea must present a passport.
A passport is the best international identification and may help you to avoid delays when crossing the U.S. Mexico border.