Vote from political action card

Who gains the vote from a political action card? The acting minion, or, as the rulebook suggests, the minion’s controller? Can the controller abstain, or is this gained vote compulsory? 

The methuselah is the one gaining the vote from the political action card as per the rulebook like you are saying.

Gaining votes and ballots doesn’t mean they have to be cast/used…abstaining is a valid option.

Everything about this is very well covered in the rulebook.

I agree that this is all well covered in the rule book, except the term "abstain." I will clarify my question: can a methuselah officially "abstain" from voting, or do they simply choose not to cast a vote? 

In fact they simply choose to not cast their vote. That's why you may choose later during a referendum to cast their vote in favor or against, changing your vote after being in favor or against is not allowed.

Followup question:
Can a methusalem allocate their "personal votes" per source, or must a methusalems votes be cast all ot once, like votes of a vampire can not be split?

So, I'm really trying to understand the term "abstain." It seems like "abstain" means "must not cast votes," rather than "chooses not to vote." Vampires in topor, vampires who participated in a tied Prisci sub-referendum, and vampires where card text forces abstaining are the only instances of "abstaining" that can happen in the game. Thus, Methuselahs are not able to "abstain" (ie, the concept of forcing methuselahs to not cast gained votes doesn't exist in the game). Do I have this correct?

My original question stems from the card text on Kindred Coercion: 

"The affected vampires may choose to abstain if they have not already cast their votes and ballots"

This text led to discussion about whether a Methuselah (rather than a vampire) can choose to formally "abstain" instead of simply choosing not to vote. A very dumb argument ensued, and everybody was confused about the term "abstain." Thus the reason for my original question.