We live in a consumerist society, which means that we are primed, so to speak, to think of good and bad in terms of consequences. Let consequentialism be understood as the following:
(1) Things are good and bad wholly insofar as they result in overall good or overall bad consequences.
We also have a tendency to think of social problems in terms of faction or party, broadly understood. Partisanship works on polemic, which involves assertion in advance of proof, presumptive evaluation according to one's faction's standards, and the attempt to achieve practical results despite opposition from other factions. To achieve practical results requires getting support for what one regards as good and resisting the opposition of those who try to prevent one from doing so. On the basis of these characteristics of partisanship, we can say that the following is going to be treated as true in a highly partisan context:
(2) The opposing factions are deliberately doing bad things.
From (1) and (2) it follows:
(3) Therefore, the opposing factions are deliberately achieving bad consequences.
But bad consequences are bad consequences for people, which can be called harmThus:
(4) To achieve bad consequences is to do something that harms someone.
From (3) and (4) it follows;
(5) Therefore, the opposing factions are deliberately doing things that harm people.
Now, we often make a distinction between doing something that harms someone and harming someone; but we do this when we are assuming that intention, not consequences, are the essential problem. If (1) is true, then there's no difference in badness between deliberately doing something that harms someone and deliberately harming them -- what makes something harming is the result, not the intention. And in partisanship, asserting in advance of proof and evaluating presumptively on one's own standards, not the opposing party's, (5) easily slides into
(6) Therefore, the opposing factions are deliberately harming people.
But who are they harming by being opposing factions? We got here by focusing on the fact that as partisans we are aiming at what we deem good and resisting the opposing faction's attempt to stop us from achieving good. This good may be for ourselves or for others. So:
(7) Therefore, the opposing factions are deliberately harming either us or people we are trying to help.
But we have a name for being the target of deliberate harm:
(8) People who are deliberately harmed by someone are victims.
Therefore from (7) and (8) we get:
(9) Either we or the people we are trying to help are victims of the opposing factions.
Now, of course, all of this is still in advance of proof; it is in the air; it is hypothesis without confirmation. So what do we do as partisans? We look for bad consequences, either for us or the people we are trying to help, which we can pin on the opposing factions, because we are resisting those opposing factions who are trying to stop us from doing good and achieving very good goodness.
Thus it seems that when we combine two things, a consequentialist view of good and bad, and partisanship or factionalism, we naturally get an incentive to start classifying people as victims of the opposing factions. Providing consequentialist justifications for partisan positions in a manner usable in practical politics inevitably involves simplification, so finer distinctions by which one might avoid the slide from (1) and (2) to (9) are hard to maintain; and the simplest consequentialist justifications for anything in politics are those that appeal to grave harms. It's not generally going to be sufficient to insist that the people opposing you are insisting on slightly inconvenient things. And in a factionalist context, you aren't waiting for proof of harm; faction works by polemic, and polemical assertions are in advance of proof. It is not proportioned to evidence by any strict standard, but asserts freely on the basis of what the evidence can seem to suggest.
The consequentialist can indeed avoid all this; and, for that matter, partisanship does not automatically head in this direction, either. The combination of the two is a bad recipe for society. Factionalism is hard to stamp out; it is much easier to reject consequentialism. So, all other things being equal, in politics one should reject consequentialism.
Of course, there are genuine victims; but victimhood is going to be understood in a different way on a non-consequentialist approach; non-consequentialists will generally put more emphasis on intent and kinds of action, for instance, which makes the slide between (5) and (6) harder.