What's the adjective for preferrers? Here's the word you're looking for.
Included below are past participle and present participle forms for the
verbs prefer, preference and preferr which may be used as adjectives within certain contexts.
Of or relating to a votingsystem in which the voters are allowed to indicate on their ballots their preference (usually their first and second choices) between two or more candidates, so that if no candidate receives a majority of first choices the one receiving the greatest number of first and second choices together is the winner.