We study a two-alternative voting game where voters’ preferences depend on an unobservable world state and each voter receives a private signal correlated to the true world state. We consider the collective decision when voters can collaborate in a group and have antagonistic preferences—given the revealed world state, voters will support different alternatives. We identify sharp thresholds for the fraction of the majority-type voters necessary for preference aggregation. We specifically examine the majority vote mechanism (where each voter has one vote, and the alternative with more votes wins) and pinpoint a critical threshold, denoted as \(\theta _{\texttt {maj}}\) , for the majority-type proportion. When the fraction of majority-type voters surpasses \(\theta _{\texttt {maj}}\) , there is a symmetric strategy for the majority-type that leads to strategic equilibria favoring informed majority decisions. Conversely, when the majority-type proportion falls below \(\theta _{\texttt {maj}}\) , equilibrium does not exist, rendering the aggregation of informed majority decisions impossible. Additionally, we propose an easy-to-implement mechanism that establishes a lower threshold \(\theta ^*\) (with \(\theta ^*\le \theta _{\texttt {maj}}\) ) for both equilibria and informed majority decision aggregation. We demonstrate that \(\theta ^*\) is optimal by proving a general impossibility result: if the majority-type proportion is below \(\theta ^*\) , with mild assumptions, no mechanism can aggregate the preferences, meaning that no equilibrium leads to the informed majority decision for any mechanism.