Sen. Tom Coburn, R-Okla., has done us all a tremendous service: He has effectively demolished many of the right's arguments against expanded background checks.

The conservative, pro-gun Coburn sent a letter to his Senate colleagues saying that he has a better proposal for expanded background checks than the one produced by Sens. Joe Manchin, D-W.Va., and Patrick Toomey, R-Pa. But while defending his proposal, he effectively destroys the argument of Second Amendment infringement as it is being applied to Manchin-Toomey.

Coburn claims that the Manchin-Toomey provisions on recordkeeping -- and their call for a fee for the background checks -- are too burdensome and suggests expanding background checks to virtually all private sales without recordkeeping and without a need to go to a federal firearms licensee to get checks done.

"As a firm believer of the 2nd Amendment," he writes, "I support the reasonable expansion" of the current system's "checks into secondary and private markets for the purpose of keeping firearms out of the wrong hands. . . . [U]nlike retailers, we as private citizens have no tool to know if the purchasers of our weapons in secondary markets (such as gun shows, flea markets, and through internet advertisements) are on the prohibited list. . . .

"To my colleagues that say any reform dealing with gun laws is an infringement on the 2nd Amendment, then I welcome a debate on your amendments to repeal the 1993 Brady Bill. . . . If prohibited people are not going to comply with any law we pass, then why should Congress make an effort to improve the reporting of disqualifying records to NICS [?] The more than $1 billion in federal tax dollars spent on creating and maintaining the National Instant Criminal Background Check System is rendered useless when a prohibited purchaser can just as easily procure a firearm from a gun show or an internet marketplace without a NICS check as they can at a gun store."

With that, a pro-gun senator has confirmed that checks are good for law-abiding gun sellers who don't want to sell to prohibited people. He's shown that the argument that expanding checks is unconstitutional is incoherent unless you also believe the current system should be repealed as unconstitutional. And he's deflated another key argument -- "criminals won't obey the law or submit to background checks, so why expand them?" -- by pointing out that the very reason criminals can continue to avoid submitting to checks (and disobeying the law by procuring guns as prohibited people) is that the loophole enables them to do so. In other words, "criminals won't obey the law" is an argument for closing the loophole!

Thank you, senator.