The U.S. Constitution expressly prohibits all governments from infringing upon the right of the people to keep and bear arms. This permits us to defend ourselves when the police can't or won't, and it permits a residue of firepower in the hands of the people with which to stop any tyrant who might try to infringe upon our natural rights, and it will give second thoughts to anyone thinking about tyranny.
The country is ablaze with passionate debate about guns, and the government is determined to do something about it. Debate over public policy is good for freedom. But the liberal progressives want to use the debate to justify the coercive power of the government to infringe upon the rights of law-abiding folks because of what some crazies among us have done. We must not permit this to happen.
The whole purpose of the Constitution is to insulate personal freedom from the lust for power of those in government and from the passions of the people who sent them there.