Fiat just means the plan is adopted and fully in effect. It doesn't eliminate the attitudes of the plan's opponents. Any argument based on that opposition, from politics disadvantages to circumvention-based solvency arguments, is fair game.
The years and years of agitation and subversion that followed Brown v. Board of Education is a good model for thinking about this: the decision was dropped, 9-0, into a climate of extraordinarily strong opposition. In some ways it didn't accomplish its goals, in some ways it unleashed truly unfortunate consequences, and there are those today who think it shouldn't have happened, that instead desegregation should've been accomplished through other means. In other words, a good, balanced, debatable controversy.
If fiat has no effect on attitude, couldn't the negative team take any
plan blocked solely by attitudinal barriers and argue that it would be reversed once it's passed? (I'm guessing that's what you mean by "circumvention-based solvency arguments.") To me, at least, this sounds abusive. Just trying to understand, here. Thanks, Dr. Srader.
Never throughout history has a man who lived a life of ease left a name worth remembering.