Just one month ago, the nation was shocked by the tragic killing of 20 boys and girls and six staff members in a Connecticut school. And now, good to his word, President Barack Obama has unveiled a series of actions designed to reduce the chances of another senseless mass killing.

We urge the president to stick with this fight; it will be a tough one. But it must be done.

Among the things we believe lawmakers should pursue:

A ban on assault weapons.

A ban on high-capacity magazines.

A ban on the online sale of ammunition.

Measures to allow local police departments easier access to federal records on gun ownership when they need to trace a weapon used in a crime.

Universal federal background checks.

Obama has called for legislation and announced separate actions he could take by executive order. With the influence of gun-rights groups, notably an unchastened National Rifle Association, still weighing heavy on Capitol Hill, the president may need to spend significant political capital to ensure a meaningful bill emerges.

We believe it’s worth it. Certainly, all those grieving families in Connecticut must believe that. We must not forget the innocent martyrs of Newtown.

Obama believes that he likely will have to take action on his own. Among the things he could do: place new limits on imported guns, encourage better sharing of mental health records and direct federal agencies to conduct research on gun violence.

A federal solution is best rather than a patchwork of state laws. But if the federal government doesn’t do its job, the states may have to. New York Gov. Andrew M. Cuomo and lawmakers in that state on Tuesday passed a number of changes to gun laws, including expanding an existing ban on assault weapons and measures to prevent people with mental illness from acquiring firearms.

In Wisconsin, where Republicans control both houses of the Legislature, any effort to tighten existing laws or write new ones is going to be difficult.

“My heart breaks when I watched what happened,” Assembly Speaker Robin Vos (R-Rochester) said in a recent meeting with the Editorial Board. “We are going to look at our mental health laws to see if there are things we could tighten up to ensure that every single person who does not have the legal ability to own a weapon doesn’t have one.”

We’ve said it before: There is no reason civilians need assault-style rifles. No reason they need to be able to buy ammunition online. No reason they need high-capacity magazines. No reason they should fear background checks.

No reason at all. The nation needs its representatives to overcome their fear of the NRA and similar groups — and do the right thing.