It was last summer when the House passed legislation to ban assault weapons for the first time in nearly two decades. The vote was close — 217 to 213 — and the then-Democratic majority was not entirely united: Five Democrats voted against the legislation that soon after failed in the Senate thanks to the chamber’s filibuster rules.

Among the five was Rep. Jared Golden of Maine, who’s earned a reputation as one of Congress’ most centrist Democrats. His opposition was not entirely surprising, given that Golden represents a rural district where new gun safeguards are not altogether popular, and Democratic leaders didn’t push him too hard, especially since his vote wasn’t necessary to pass the bill.

That was 15 months ago. As NBC News reported, Golden’s position has since evolved.

In a reversal, Democratic Rep. Jared Golden of Maine said he now supports a ban on assault-style rifles following shootings this week in his home state that left at least 18 people dead. During a news conference Thursday, Golden discussed his previous stance on legislation largely backed by fellow Democrats that would prohibit assault weapons and said he was wrong to oppose those measures.

“I have opposed efforts to ban deadly weapons of war, like the assault rifle used to carry out this crime,” Golden said, adding, “The time has now come for me to take responsibility for this failure. Which is why I now call on the United States Congress to ban assault rifles like the one used by the sick perpetrator of this mass killing in my hometown of Lewiston, Maine.”

If recent history is any guide, some will probably criticize Golden for taking so long to arrive at this position, but it’s also true that his comments and reversal offered a rare sight. I’ve watched Congress for quite a while, and I can think of very few instances in which members have expressed regrets and contrition like this.

Will the Maine Democrat’s reversal change the legislative realities on Capitol Hill? Probably not. The Republican-led House will almost certainly continue to ignore calls for new safeguards to prevent gun violence, and in the Senate, GOP-led filibusters also stand in the way of governing.

But that’s partly what makes Golden’s new position even more notable: He’s changed his mind, not to win an election or in response to partisan arm-twisting, but because he’s concluded it’s the right thing to do. What’s more, he’s in a competitive district, and Golden no doubt realizes that the right will use his new position as the basis for attack ads. The three-term lawmaker did it anyway.

With any luck, this kind of leadership might inspire others to do the same thing.

Among those who might learn from Golden’s example is Republican Sen. Susan Collins of Maine, who on Thursday refrained from endorsing an assault weapons ban, though she is on board with bans on high-capacity magazines.