Speaking in Minneapolis yesterday, President Obama repeated his call for requiring all gun buyers to undergo background checks, limiting the capacity of newly produced magazines, and reinstating the federal ban on "assault weapons." Here is how The New York Times describes his speech:

In a city once called "Murderapolis" for its homicide rate in the 1990s, the president cited successful gun-violence prevention efforts here as evidence that new national laws are needed to reduce the number of shootings across the country....

In the 1990s, Minneapolis experienced an explosion of drug- and gang-related violence, which led to a series of local measures aimed at reducing gun violence that has brought down the city’s murder rate.

What sort of measures? The only example the Times offers is "programs directed at rehabilitating young people who have committed violent crimes." Or as Obama put it in his speech, "You launched a series of youth initiatives that have reduced the number of young people injured by guns by 40 percent." In what sense does the putative success of those initiatives reinforce the case for the gun control measures Obama is pushing?

For those who are not persuaded that we need a new, broader ban on "assault weapons" because "youth initiatives" worked in Minneapolis, Obama argued that "we don’t have to agree on everything to agree it's time to do something." But we do have to agree on something to agree it should be done, don't we? Maybe not: 

No law or set of laws can keep our children completely safe. But if there's even one thing we can do, if there's just one life we can save, we've got an obligation to try....

The only way we can reduce gun violence in this country is if the American people decide it's important....

That's why I need everybody who's listening to keep the pressure on your member of Congress to do the right thing. Ask them if they support common-sense reforms like requiring universal background checks, or restoring the ban on military-style assault weapons and high-capacity magazines....

And tell them now is the time for action. That we're not going to wait until the next Newtown or the next Aurora.  We're not going to wait until after we lose more innocent Americans on street corners all across the country.  We're not going to wait until somebody else's father or son are murdered....

If there's even one thing we can do to keep our children and our community safe, if there's just one step we can take to prevent more families from feeling what they feel after they've lost a loved one, we've got an obligation to take that step...

There won't be perfect solutions. We're not going to save every life. But we can make a difference. And that's our responsibility as Americans.

Obama never explains exactly how the laws he wants would prevent mass shootings. But if they would, he says, don't we have a responsibility as Americans to support them? And since "the only way we can reduce gun violence in this country is if the American people decide it's important," we will reduce gun violence if we decide it's important, no matter what harebrained legislation results from that sentiment. Above all, we must act now, before anyone has time to spot the president's logical leaps.