Votes of acting minion during political action

During our most recent playmeet, a heated discussion arose concerning the votes of the acting minion taking a political action.

Basically one party claimed that minions taking a political action must always vote in favor of the following referendum, while the other was conviced that voting for or against a referendum was entirely up to the controller of the acting minion.
While I was neither party, I am inclined to agree with the second, because of the following passage form the rulebook(6.3.2, Polling):
"All Methuselahs may now cast any votes and ballots they have (see below) at this time, in any order. They call out their votes and ballots freely, and there is no obligation to cast votes or ballots."

While it more than often makes perfect sense for a minion playing a political action to vote in favor of the following referendum, are there any rulings stating that doing so is mandatory?