What the theorem says
In settings with at least three alternatives, Arrow's theorem studies rules that convert individual rankings into a collective ranking.
Under unrestricted preferences, Pareto efficiency, independence of irrelevant alternatives, and non-dictatorship, the theorem says no such rule can satisfy all of those conditions at once.
What problem it exposes
The theorem exposes a structural limit of ordinal aggregation because a ranked ballot says what comes before what, but not how intensely a voter cares about the difference.
That limit does not make democracy incoherent. It means every decision rule makes tradeoffs, and those tradeoffs need to be explicit.
Where Nicolas fits
Nicolas does not turn individual rankings into a social ranking. It asks for costly support and opposition intensities under a finite voice budget.
That moves the decision into a different information model. It is a practical way to measure strength of preference when intensity matters, not a universal escape from impossibility.