.. you are allowed to play a Cryptic Rider on an automatically passing referendum. So you can (for example) start playing a Dia de los Muertos first. Then you can call a vote, then play Cryptic Rider during that referendum making the next referendum successfully called passing automatically as well. And of course, you can repeat this until you run out of Cryptic Rider and political action cards (and vampires calling these referendums).
On the other hand, it's not possible to play Delaying Tactics during a political action that is automatically passing since there's no referendum during which the card can be played [LSJ19980107].
Reference: VtES Usenet Newsgroup [LSJ20031009].