Mike Butler: Tide turning for same-sex couples?

Fair Go presenter Alison Mau put her case for same-sex marriage, on TV ONE’s Close Up on Wednesday, by claiming that "there's a tide of feeling globally about this issue”. As a woman in a same-sex relationship wants to get married, Mau said “it's the fact that I could get married 15 years ago when I married for the first time...and suddenly I can't marry who I want to marry now. And that seems odd and silly and outdated."

Is there an actual tide of feeling, or is it that the tide of feeling involves a few luminaries (United States President Barack Obama, New Zealand Prime Minister John Key, and now Mau) supporting same-sex marriage for political or other reasons?