This school shooting thing is a created phenomenon though, from media hype and other factors. I went to high school in the 80's, and it was common for guys to have rifles hanging in the back windows of their trucks at school, especially during hunting season. Nobody shot up the schools or even thought of it.
List of school shottings in the US So, not really true that nobody shot up schools or even thought of it. What' happened in the late 90s was (1) there was a school shooting where several people died at once, (2) it was a clearly coordinated attack with multiple people, and (3) there was a 24 hour news cycle that kept tried to cover every possible angle for every bit of sensationalism. Like you say, this then created the phenomenon of mass school shootings even though they were a thing of the past.
Also, I very much doubt that list is at all inclusive, especially when you get further back than the 60s. Why? Because before then you didn't have news reporters that could beam a video broadcast of a story to the whole nation within a day or two of an event. So, most stories were in the local/state news and that's it.
Fast forward to today, and everything can get amplified. Crime rates going down? People don't believe it because we have instant access to the worst events in the country. Mayberry wasn't a carefree little hamlet. In Mayberry there were rapes and murders. On a per capita basis, it's probably around the same rate as any city. Of course, rural towns don't want to advertise those things, especially if a local official was involved, and it's a lot easier to hush up about it--especially in the past.
So, while I don't entirely disagree about the sentiment at some level that mass school shootings are a new thing, in a lot of ways they aren't. We're just a lot more aware of them. Maybe that awareness makes some would-be killers more apt to engage in something they only fantasized about. Certainly if they know they can get the means to do it because laws are lax, they're inclined to do it even if they never go through with it.
@weatMod - So, yea, that's a stupid argument. The reason to legalize drugs is that, at least directly, drugs only harm the user. Indirectly it can harm people in the same way guns can--which is an argument to ban harder drugs. Then again, this was the main argument to banning alcohol--people blamed the drink instead of the drinker who chose to keep drinking and beating his wife.
The other point is that people will keep buying drugs even if they're banned because they consume them on a regular basis and it makes them happy/less-sad. The same really can't be said for banned guns except in very isolated cases--die hard collectors and the like. Practically, though, drugs and guns alike can be accidentally used and harm others, which is why most drugs require prescriptions. One could argue that this recognition of the danger of drugs and their misuse would be good reason to have similar rules on guns as well as potential standards on banning some because they're too dangerous.
In the end, it's not about the notion that criminals won't get access to drugs/guns even if they're banned but to make them sufficiently hard to get and sufficiently taboo that people won't want to get them. It obviously works to various degrees with it working pretty horribly with marijuana. It's why if they banned all guns, then people would have the same reaction to the war on drugs: lots of effective resistance to the law and a general lack of respect for it.
Of course, there's always people extreme enough that they want all of both or all of one and the other banned. So, *shrug*.
