I'm not sure I get where you are going. It might be a divisive issue but saying that simply because it comes up and you think something else is more important doesn't mean it is being used just to be divisive.
So the amount of money spent means people don't really care or it's an illegitimate topic or something?
I'm suspicious of some topics and the support they get myself, but your approach here seems much too fast to dismiss a topic that maybe you don't like. It's way too easy to just say something is not organic or illegitimate when the issue is unpleasant rather than really deal with it. I don't know if anyone has a good way of getting their finger on legitimate, or topics that are more "important" than others in a democracy.
Really, it's more than just being divisive that's at issue. At core you need to consider two factors.
Assault Weapons Ban is a similar thing. Something people really care about, but can go months or years without thinking about it.The point is these things both provide support and distractions. But, when one side gets into power they don't actually try and change much.