I thought this is a very good article by two lawyers from the Reagan and GWB administration. Explains to the fudds, a lot of them read the Wall Street Journal, the second amendment.
They were explaining how unconstitutionally having insurance for a gun would be:
David Rivkin and Andrew Grossman: Gun Control and the Constitution - WSJ.com
They were explaining how unconstitutionally having insurance for a gun would be:
The courts, however, are no more likely to allow government to undermine the Second Amendment than to undermine the First. A state cannot circumvent the right to a free press by requiring that an unfriendly newspaper carry millions in libel insurance or pay a thousand-dollar tax on barrels of ink—the real motive, in either case, would be transparent and the regulation struck down.
David Rivkin and Andrew Grossman: Gun Control and the Constitution - WSJ.com