Advocates for ranked choice voting from both parties say their pitch should be a no-brainer: It fosters intraparty unity and roots out extreme candidates as polarization thrives even within Democrats and Republicans themselves. But it’s far from that simple.

A ballot-casting system that’s gained traction at the state level, ranked choice allows voters to pick multiple candidates in order of preference rather than just one. The candidate must receive a majority of first-choice votes to win, otherwise the votes are reallocated in runoff rounds to eliminate competitors until one secures a majority.