On Expressing Majority as a Majority of Majorities

If k < n, can one express the majority of n bits as the majority of at most k majorities, each of at most k bits? We prove that such an expression is possible only if k & n = n. This improves on a bound proved by Kulikov and Podolskii [KP17], who showed that k & n. Our proof is based on ideas originating in discrepancy theory, as well as a strong concentration bound for sums of independent Bernoulli random variables and a strong anticoncentration bound for the hypergeometric distribution.