If that is what charges of "manipulation" actually corresponded to in practice, then one could just punish the actual instances of deception, dishonesty, or withheld information (DD&WI). But, in fact, it's rather rare for people to object to DD&WI when it is used to support a position they agree with, and in these situations they essentially never call it "manipulation". (If your friend Bob withheld information to convince someone of a political position you strongly agreed with, can you imagine yourself saying "Bob manipulated him"? Of course not, because "manipulation" is understood to mean "...for something bad".) In other words, "manipulation" is only used as an additional charge, beyond DD&WI, for things we disagree with.
(One could argue that we correctly have laws that punish actions based on the action's impact, like attempted vs. completed murder, and that "manipulation" could be for when DD&WI is deployed effectively. But again, no one ever calls this "manipulation" when it's for something they agree with, and they never claim that effective DD&WI of this type should be punished more harshly than ineffective DD&WI.)