Could this time be different? Sure. The movement to regulate guns has never had children as its spokesmen before, and they could prove to be just as powerful as last weekend’s marchers are hoping. If the conventional wisdom that Democrats are going to gain House seats and governorships this year proves true, then it is highly likely that the NRA will have fewer allies in elected office next year simply because of that.

But neither good Republican years nor good Democratic years have changed the fundamental facts of gun politics. The main reason we don’t have more restrictive gun laws on the books is that people who oppose them are more likely to vote on the issue than people who support them.

No law of nature says that fact has to hold true forever. It could change if, for example, enough people who think that assault weapons should be banned but who have typically voted for NRA-backed candidates, or haven’t voted at all, alter their behavior.