As expected, the three major policy changes that President Obama recommended today, ostensibly in response to the Sandy Hook massacre, were a renewed (and broader) federal ban on "assault weapons," a 10-round limit on magazine capacity, and background checks for all transfers of firearms, except those between relatives. Obama supported these policies before the Sandy Hook massacre, he supported them immediately afterward, and now, after a three-week fact-finding charade overseen by his vice president, he still supports them. The unanswered question, as I said this morning, is why anyone else should.

Reflecting the president's magical thinking about gun control, The New York Times claims that renewing the limit on magazine size that expired in 2004 (a subject I discuss in my column today) "would eliminate the 30-round magazines that were used in Newtown as well as other mass shootings at Virginia Tech, a movie theater in Aurora, Colo., and a congresswoman’s public event in Tucson, Ariz." No, it wouldn't, unless the government somehow manages to confiscate all of the "large-capacity" magazines already in circulation. Under the earlier law, something like 30 million pre-ban magazines holding more than 10 rounds were still available, and that number surely is much larger by now. The government will also have to stop would-be mass murderers from making their own magazines, which is not that hard to do (especially if magazine replacement parts remain legal) and is only getting easier, thanks to 3D printers

Likewise, barring mass confiscation, a new "assault weapon" ban won't eliminate whatever guns fall into that arbitrarily defined category. Even if it did, it would not matter, since killers would have plenty of equally lethal alternatives. Background checks could not, even theoretically, stop most mass shootings, which typically are perpetrated by people who do not have disqualifying criminal or psychiatric records. Those who do can always avoid background checks by obtaining guns through others means (as Adam Lanza did, by using his mother's legally purchased firearms). Speaking of which, how will the government make sure that every nonfamily transfer of firearms involves a background check unless it keeps track of who has what guns at any given moment? A national registry of guns (and magazines?) would be necessary to enforce such a requirement. Which, come to think of it, would make mass confiscation much easier if gun controllers ever decide to get serious.

You can read Obama's policy proposals here.