Crushing Grip (Potence Votes)

Well, it would be more thematic (and funny) to have a card like:

Negotiations
MOD/React
1
Only playable during a referendum, before a minion is about to cast their vote or ballot. Only one negotiations can be played each action.
Burn 1 pool to enter combat with a minion controlled by another mathuselah that is about to cast their vote or ballots.
Deal 3 damage to a minion controlled by another mathuselah that is about to cast their vote or ballots.

They can't cast their votes if they don't have teeth.

The idea and art idea are solid, but hitting for damage due to not agreeing fits mono better. Maybe could be similar but a reaction and stop pool gain during the action to stifle voter cap?

how about something like this:

Implied Violence

1
Only usable during a referendum.
the acting vampire burns 1 blood if the Referendum passes.
as above, and Cancel an action modifier that gives the acting Vampire additional votes.

self blased version seems way more fitting too. Also, another thing to not stop minions for voting, but for benefiting from it (and also helping a combative potence deck) could be:

Implied Violence (as self biased above)

1
Only usable during a referendum.
the acting vampire burns 1 blood if the Referendum passes.
as above, and the acting vampire cannot gain any blood this action.

This stops big votes from replenishing with an awe+voter captivation, but doesn't stop them from actually voting or gaining pool, so the voting deck still works, but is vulnerable agains any further combat, which fits theme.

Well, this time, this is crap...

You play a card and pay a blood to make another vamp burn a blood only if there is a referendum and it passes (so for the record, you still lose 5 from a parity shift or anything that you would not want to happen).

And the superior version works only against voter captivation...

@jblacey, Ratadin, James, Reverend, SelfBiased:

You guys get what I'm trying to do, even if we disagree about the specifics. It's an abstracted / metaphorical Potence card. Potence doesn't have to be resigned to just punching people in the face, or breaking buildings and stuff, but can be the implied threat of violence. Names like "Crushing Grip", "Negotiations", and "Implied Violence" all hints at that idea.

However, Ratadin and SelfBiased, I think your card ideas are too underpowered. Like Timo said, the burn 1 blood to do 1 point of damage isn't a good exchange rate, especially if the requirement is to let a referendum pass (or a bleed in the case of a card like Touch of Pain, which is wallpaper. Neat idea, but still wallpaper.)

How about a compromise?
Negotiations
Reaction
Only usable during a referendum or immediately after resolution of a political action.
Cancel the effects of an action modifier card as it is played.
Lock this reacting minion and enter combat with the acting minion. If the acting minion leaves the ready region as the result of combat and a referendum was taking place, it fails. (Otherwise, the referendum and/or resolution continues as normal.)

This blends the previous suggestions plus jblacey's submission. Maybe the inferior/superior should be reversed? Inferior cancels stuff like Bewitching Oration, Voter Cap, and even Freak Drive. Superior can be used as a sort of back-rush to help combat decks do their thing, as jblacey suggested.

@Timo: I don't want to see Potence become a toolbox discipline, but having a little bit of flexibility should be fine. Also, you say:

"Potence is good at smashing things. It is normal, flavour and should stay at this place."

But one of the best combat cards (Target Vitals) has no requirement. Every vampire gets a Potence-flavoured card without needing the discipline, which is lame IMO.