Read Noam Sheiber's smart thoughts on why background checks on gun purchases were doomed from the start.
[G]uns tend to be remote from the experience of most gun-control supporters. This is true even after a horrific act of gun violence like Newtown. Though every parent was briefly traumatized by the thought of their child being massacred at school, only a small fraction of parents (and especially parents who vote) are directly or even indirectly affected by such crimes.
This means that, even when overwhelming majorities of Americans support a specific gun-control measure, their support is shallow. Guns and gun violence just aren’t something they spend a lot of time contemplating. The voters who oppose gun control, on the other hand, (hunters, shooting enthusiasts, crazy people) devote a good bit of mental energy to firearms. As a result, they’re easily mobilized by the interest groups who spend all their time on the matter (namely gun-makers and lobbyists).
As I mentioned yesterday, 90% of Americans favor background checks. But only 4% rank guns as the most important issue in the country. You can bet vulnerable senators looked at these numbers and calculated they'd rather face Michael Bloomberg than risk the wrath of gun owners, sportsmen, and the National Rifle Association.