A real discussion of what to do about mass shootings would begin with three competing values: rights, risk and reward. First, the rights: Americans have the right to bear arms, not only for self-defense, but in preservation of a free society. The founders recognized it, and their logic is still relevant. There are societal rewards to gun ownership by responsible people, including deterrence of crime and prevention of mass shootings (an attempted mass shooting in San Antonio was thwarted by an off-duty police officer who shot a would-be perpetrator four times over the weekend, for example).
There are risks to firearms, too. They are far more powerful than knives. They have a higher capacity for damage, and they are more efficient. That's why the proper solution would be to allow responsible gun owners to keep their firearms, while preventing non-responsible gun owners -- especially the mentally unstable -- from obtaining theirs.
These decisions must be carefully calibrated. They ought not be made in haste or in the heat of passion. We ought to let Sandy Hook stir us to action -- indeed, we cannot avoid letting it do so. But we cannot let that emotion drive us into idiotic laws that violate rights and make people less rather than more safe.
But this is not a discussion the left wants to have. They are more interested in demagoguing the issue by slandering conservatives as heartless and unfeeling. That's not just insulting to conservatives. It's insulting to the murdered children, who deserve more than to be used as a political chip in an attempt to ram through an ill-conceived agenda.