In some states, homosexuals can legally get married and justices of the peace, being government officials, are forbidden to refuse to officiate.
Which leads to an interesting option. Its called freeom of speech. Members of the state legislature have a right to express their opinions about pending legislation, and justices of the peace have as much right to express their opinions about a marriage.
If you solemnize legitimate peoples marriages in the gazebo out back, tell the queers they can only have the ceremony in the garage. Its still legally binding.
If you travel to a banquet hall to solemnize legitimate peoples marriages, and you are required to do the same for queers, tell them ahead of time how you will perform your official duty:
Dearly beloved, there is obviously something seriously wrong with these two queer homos, and I cannot imagine why anybody, in their right mind, would be gathered here today to witness this, but they want to get (ahem) mawied. So, without further ado, as Gary Gilmore said on 17 January 1977, as he stepped before a Utah firing squad, Lets do it.
Faggot number one, John, do you take Faggot number two, Richard, to be your lawfully wedded spouse?
John: I do.
Faggot number two, Richard, do you take Faggot number one, John, to be your lawfully wedded spouse?
Richard: I do.
I therefore pronounce you legally married. Now let me get out of here before I puke.
If they dont want it to go like that, they can find another J.P. If all they want is to be legally married then thats what they got.