Here is the story.
Even if it passes next year, there will likely be a referendum that same year on whether to keep it. Currently, people in Maryland are in favor of same-sex marriage by 51% to 41%. But so far, same-sex marriage has not survived a referendum in any state. The horrifying (albeit untrue) ads start, and people respond.
I feel frustrated enough that my marriage is subject to disapproval by popular vote. (Just how many people would want to see their marriages voted up or down by the public?) And doubly so when I learn that not even half of the legislature in a reasonably liberal state is willing to vote in my favor.