Ostrogorski's paradox is a voting paradox studied in social choice theory.
[1] The paradox states that if each voter during an election voted for the political party with which they agreed on a majority of issues, then it is still possible that a majority of voters will disagree with the winning majority party on every issue.
[2] The paradox resembles the structure underlying the Condorcet paradox and Simpson's paradox[2] and it has been proved that in every instance of Ostrogorski's paradox there is an underlying Condorcet paradox.
[1] It is named after Russian politician and political scientist Moisey Ostrogorsky.