Universalizing Tactical Voting

I regularly come across two objections to tactical voting, i.e. voting for Lesser Evil rather than Good in hopes of defeating the Greater Evil candidate.  One objection is just the standard worry that individual votes lack instrumental value, debunked here.  More interestingly, some worry that tactical voting is positively problematic, morally speaking, on grounds of its putative non-universalizability.

On one version of the worry, tactical voting involves (something approaching) a contradiction in the will, insofar as even if those who most prefer Good constituted a majority, they could get stuck in the inferior equilibrium point of all (unnecessarily, and contrary to their collective preference) supporting Lesser Evil.  On another version of the worry, tactical voting involves (something like) a contradiction in conception, insofar as it involves responding to how others plan to vote, which might seem to depend upon those others voting non-tactically, i.e. not waiting to first learn how you plan to vote.


To avoid either worry, it suffices for tacticians to follow Regan's co-operative utilitarianism (which is, in general, the correct theoretical solution to any sort of coordination problem).  To wit:

(1) Identify those who are willing and able to cooperate with you (by following this very decision procedure) in pursuit of the best collectively attainable outcome.

(2) Determine the best available total plan of action for the group of cooperators, given how non-cooperators will actually behave, then play your individual role in said plan.

In the first problem case: If a majority of the electorate is willing and able to cooperate with you, then correctly following the above procedure entails (i) that they will recognize themselves as forming a majority, and (ii) will follow the best plan available on that basis, viz. electing Good.  Your group of cooperators will only vote for Lesser Evil on the condition that they are not in a position to collectively elect Good (who is, by stipulation, better).  So: no problem.

The second case is a bit trickier.  I take it that we are to imagine difference sub-groups, each of which attempts to cooperate in voting tactically to best achieve their (differing) goals.  Perhaps 40% unconditionally support Greater Evil, and 30% each support Good and Lesser Evil, whilst still preferring the other over Greater Evil.  How should the G and LE groups vote (given their values)?

Since they have different goals, they do not count as fully mutual cooperators.  All we can do is consider each group separately.  In each case, what the members of a group objectively ought to do will depend upon what the other group does.  But that's not a problem, since there is after all a fact of the matter as to what the various individuals will end up doing, and so the above tactical decision procedure will (separately) determine what they all should have done (given their values).  It can be summarized as saying that each group should vote for whichever candidate the other group votes for, whereas determining which candidate that is is a matter outside of moral theory.  (It may instead be determined by whichever group is better able to position their candidate as the 'default' alternative to the Greater Evil.)

While it would of course be unfortunate if it turned out that the Lesser Evil folks were able to outmaneuver the Good folks here, that would just be a sad fact about the world and not any sort of indictment of tactical voting per se, or so it seems to me.

Is there some residual problem that I'm missing here?

(The practical problem -- how to act given incomplete information, etc. -- is a different one from the theoretical problem I focus on here.  It's obviously highly non-trivial to actually identify and co-ordinate with like-minded others.  But a rough-enough approximation might be achieved by answering opinion polls with your truly most-favoured candidate, and only in the final instance voting for the most popular lesser-evil candidate.  That way if a sufficient number of tacticians really support Good, then this will show up in the polls and they can vote accordingly.)