How is it legal for people to vote on gay marriage,the minority is supposed to be protected from the majority?

can someone with legal knowledge explain this, i thought our government is supposed to protect the minority from the majority by providing everyone equal rights.Immigrants can come to our country and vote on who i can and cannot marry i don't get it, it has nothing to do with religion or children. so their are no arguments, it is no ones business who i choose to marry. it is just basic fairness, everyone deserves equal rights.