The "mini-max" regret rule is a not-quite-utility-maximization rule that says you do the following: ask yourself, what is the maximum amount of regret you might feel about the choices you might have made, after all the dust settles? Make the choice that minimizes that.
This rule comes about as a solution to the fact that it is irrational for you to vote. No, I don't give a flying fuck if everyone thought that way because that isn't the issue. You only choose for yourself, and when you try to change the subject by switching from one person to multiple people, you are implicitly accepting the premise that I am right, and just don't want to come to grips with the reality of that fact. Tough shit. Voting is irrational. Deal with it. The probability that you will swing the outcome of an election is lower than the probability of being killed in a traffic accident on the way to the polling place. If you vote, you are being irrational. Your vote will not affect the outcome of the election, unless you are voting in some small, podunk local election that doesn't matter anyway, in which case there aren't any cars anyway, so there's nothing to fear. You don't matter. Then again, neither do I.
Yet, lots of people vote, and a lot of people are uncomfortable with the reality that voting is irrational, so rat-choice scholars (yes, that's the term) have tried to rescue the act of voting from the depths of irrationality with pseudo-economic tricks. One such trick is the "mini-max" regret rule. How badly would you feel if the candidate you hated won by one vote, and you hadn't voted?* Pretty shitty, right? Voting is a relatively low-cost activity, so you vote in order to minimize that maximum regret. Mini-max regret.
What would this suggest for Republicans in Congress right now? This is sort of the same situation for them that I argued Comey was in, as far as the mini-max regret rule, back in October. I have since updated my assessments of Comey, but the basic point is that the worst case scenario for congressional Republicans is that Trump really is deeply in bed with Russia, and that he fired Comey to cover it up, and that congressional Republicans are helping Trump cover everything up by refusing to investigate, and that a real smoking gun will eventually come out, like a recording of a phone conversation between Trump and whatever Russian spook recruited him where Trump admits to everything. That kind of thing could bring down the whole fucking party.
As I suggested yesterday, the best way for individual Republicans to ensure that they survive whatever the fallout may be here is not to play along with Trump, and instead to call for a full investigation. That is what the mini-max regret rule would suggest. The fact that we are seeing so little of that here is telling.
Again, more to come...
*Technically, your vote here would have resulted in a tie, and the procedure in this case depends on institutional rules. Similarly, the effect if your abstention had resulted in a tie depends on institutional rules, but the point is that your vote, in this unlikely event, is the difference between certainty and uncertainty.