Sounds like they were faced with the same challenge we are. Trying to choose the lesser of two evils. Let’s see who will do the least amount of harm? Nothing will change in Mexico. It will continue it’s downhill slide into the abyss.
The difference is that our incumbent president is more closely aligned with the PRI.
Lewis Black's observation applies just as well in Mexico as it does here:
An election is like choosing between two disgusting, foul-smelling buckets of sh**. On of them is going to be with you everywhere you go 24 x 7. Your job is to pick which one you think is going to be less offensive 4 years from now.