You know, far from me to take away the people's right to make stupid decisions, but what baffles me is the (usual) reference to family and having children. In this case it's not getting into the details of what and how, but it usually seems to me to boil down to one of two stupidities:
1. Monkey see, monkey do. Those kids see two guys holding hands or some rainbow cookies and next thing you know, BAM, they're gay too.
2. If children ask about it, there is no possible way to answer other than going into excruciating detail and/or them ending up with vivid mental image. 'Cause, you know, if they see a boy and a girl kissing you can just tell them "they love each other" and they won't end up with a whole porn film in their head about it either, but if they see some rainbow cookies there's either no way to avoid telling them all the details of what gays do or no way to avoid them getting a mental image of that.
Really, the reference to obscenity makes me suspect #2.
I mean, really, for lack of a better definition of obscenity, I'll turn to the ruling by Chief Justice Warren Burger: "The basic guidelines for the trier of fact must be: (a) whether 'the average person, applying contemporary community standards would find that the work, taken as a whole, appeals to the prurient interest, (b) whether the work depicts or describes, in a patently offensive way, sexual conduct specifically defined by the applicable state law; and (c) whether the work, taken as a whole, lacks serious literary, artistic, political, or scientific value"
Even skipping past the rather offensive necessity of ruling the LGBT movement as devoid of political value to meet point C, there's no way to get past A and B without essentially requiring that anyone who sees the rainbow cookies instantly gets a whole gay porn film going in their head about it.