Why is President Obama pushing the gun issue? For John Hinderaker, the co-proprietor of the excellent Powerline blog, it's a mystery. "I understand demagoguing an issue," he writes, "but don't politicians generally try to demagogue issues that are popular?"

I can think of two possible reasons Obama is investing so much political capital on the gun issue. One is that he is acting out of conviction. Like many liberals, he would like our country to be a gun-free nation, or one with as few guns in circulation as Canada, Australia or Britain. As Hinderaker notes, that is an impossible dream in a nation in which citizens own something upwards of 200 million guns and whose Second Amendment guarantees the right to keep and bear arms, as the Supreme Court recognized in 2008. But, hey, he's the president, he has power or the simulacrum thereof, and he's going to try to make headway, however marginal or ineffective, toward his goal. That's one reason.

The other is political. He wants the Democratic Party to nominate Hillary Clinton, not the presumably unelectable Bernie Sanders, to be its candidate for president; whether he trusts or likes Clinton, she's his only chance at a Democratic successor. Clinton has been hammering Sanders on gun control, which is one of the few issues — maybe the only one — on which she clearly stands to his left. That's because Sanders represents Vermont, a state which has never had any gun control legislation, a state in which gun ownership is widespread and crime is very low. So Sanders has anti-gun control votes and statements on his record, stands which are anathema to a large majority of Democratic caucusgoers and primary voters. For Clinton gun control serves the same function that immigration played for Mitt Romney when Rick Perry was leading the polls for the 2012 Republican nomination: the one significant issue on which the candidate is more in line with the party base than a threatening rival, and therefore one he can use to disqualify him.

The fact that Obama's latest proposals would have done nothing to stop the massacres he laments, would have only a very minor effect on gun ownership and are probably a liability in a general election—all that is beside the point. This is an issue on which Obama's longstanding political conviction and short-term political calculation converge.