That there is no such thing as a 'gun show' loophole. Also, mayor, there is no 'law enforcement' loophole that you can exploit in investigating outside ofthe five burroughs. Numerous sources show that less than 1% of the guns used in committing a crime came from a gun show. Some statistics
"A Bureau of Justice Statistics (BJS) report on “Firearms Use by Offenders” found that fewer than 1% of U.S. “crime guns” came from gun shows, with repeat offenders even less likely than first-timers to buy guns from any retail source."
"Though Congress specifically has applied the background check requirement to dealers only, and specifically exempted from the dealer licensing requirement persons who occasionally sell guns from their personal collections, gun prohibition activists call this a “loophole.” Gun prohibitionists also falsely claim that many criminals get guns from gun shows; the most recent federal study puts the figure at only 0.7 percent."
With those kind of statistics, it proves that the system is working. Background checks do work and deter criminals from gun shows. Determined individuals can and will obtain firearms no matter what.
Mayor Bloomberg is a businessman and made a lot of money by the margins, perhaps he's applying that same thought to gun control. Mayor, leave the money and the guns on the table.