If these types of crimes were a mathematical problem instead of a partisan issue, they would at least be approached in a logical manner.
Facts:
You can't stop humans from doing crazy stuff or being crazy. Not anywhere in the world.
You can reduce the ability of crazy people to commit wholesale devastation by identifying they are crazy and limiting their access to really capable firepower. Knife attacks may be hard-core, but there's no question that there is a survivability gulf between the two means of attack.
People who are against gun-control confuse control with loss of freedom. You can vet people for risk. We do it to drivers all the time. You see a drunk driver and think "someone should take that guy's license", yet somehow the brain can't extend that common sense to hand held machines designed to kill things as their primary function.
Most gun enthusiasts I know are usually very sane. That's not the problem. The problem is that it's easy for the non-well adjusted to get weapons. No enthusiast should be happy about that. Actual gun advocates should be at the forefront of control and directing how it should be applied. Sane people should be able to go to ranges, or hunting or whatever, and use up lead as fast as they can spend it, because they aren't the problem, but there is an actual gun problem. I understand the anxiety, but the fight against control is really us wanting to keep our toys, and justify that to anyone who will listen, and by downplaying the key role that access to these items plays in the numbers who get taken out.