Voltaire would support same sex marriage. He believes in equality and tolerance, meaning he feels that although everyone is different, they are all equal, and should be treated fairly and equally. Therefore, he would support the LGBT community, because he sees them as they are, equal to everyone else.
I will go even further and say that we ought to look upon all men as our brothers. What! call a Turk, a Jew, and a Siamese, my brother? Yes, of course; for are we not all children of the same father, and the creatures of the same God?
Voltaire was not referring to the LGBT community when he wrote this, but the overall message of equality can be passed on to this current event.
Some of those who have advocated for same sex marriage have been met with violence, threats, and overall unfair treatment. Voltaire does not think this is right, as he wonders how you could hate someone for disagreeing with you?
It is clear that every private individual who persecutes a man, his brother, because he is not of the same opinion, is a monster...
Voltaire would be a backer of these rights, based on his want for equality and tolerance