Here is a recent post by Peg Kaplan. Here is a recent post by Bill Vallicella. Here is a recent post by Ed Feser. Here is a recent post by Steve "Cheesehead" Burri. Here is the latest batch of posts by John Ray.
Addendum: Peg's post is about homosexual "marriage." Note that Ted Olson's argument, which Peg endorses, supports polygamy as well as monogamy. That alone shows that it's defective. (There may be people who support polygamy, but I don't think Peg does—or Olson, for that matter.) The purpose of marriage, as an institution, is to bind a man and a woman for the sake of their children. It is not to affirm people's friendships.
Addendum 2: Here is a blog post by Princeton professor Robert P. George.
Keith Burgess-Jackson, J.D., Ph.D. 