So, when does one play the Trump card?

Well, that depends on how many you have and what actions the trump cards obligate.

CP is both political cancer and kryptonite. It's poisonous to handle and even more diabolical to "wield". For those who wield this as a trump card themselves are affected and infected by the content.

If it is to be CP that brings the whole fucking diseased, corrupt temple down on [their] head(s) then to those who play the card I hope they are forever changed by their actions.