Well, um...where else are you going to preach that message? Aside from the usual Sunday sermon, of course. I excerpted this from a Facebook comment stream stemming from a friend's post that "you can tell it's an election year, even weddings are getting political." Me, I think somebody's confused about the difference between morals, religion, and politics. Preachers gotta preach the Word, preferably in churches but sometimes not, and let's face it, if you don't belong to the congregation, you get no say in what the preacher says. For that matter, if you don't belong to a Protestant church or Jewish synagogue where the minister/rabbi is an employee of the congregation, you don't get even that much say; us Catholics have to sit there and put up with whatever the priest wants to dish out on Sundays.
And if you're just there for the wedding, hey, feel free to ignore what the preacher is saying. It's not your church and not your preacher. So really, what do you care? Unless, of course, you're one of those narcissistic fucks who thinks everything in the world should be done to suit you.