Sen. Bernie Sanders (I-Vt.) in Long Beach, Calif., on Tuesday. (Mike Blake/Reuters)

Paul Heintz is a staff writer for Seven Days, a Vermont newsweekly.

After a pair of mass shootings last weekend in Texas and Ohio, Sen. Bernie Sanders (I-Vt.) announced his support for a gun buyback program, declaring, “The American people are sick and tired of the NRA determining gun policy in America."

Consider it the zeal of a convert. For most of his political career, Sanders has been skeptical of federal gun control. “Everything being equal, states should make those decisions,” he told me in March 2013 after the massacre at Sandy Hook Elementary School. There’s nothing wrong with changing your mind — particularly when the underlying facts change — but Sanders and his allies have been oddly reluctant to acknowledge a shift. Perhaps that’s because doing so would undermine the central argument of his 2020 presidential campaign: that he’s been right all along and everybody else is just catching up.

Sanders wants credit for fighting economic inequality before it was cool, popularizing Medicare-for-all and opposing the Iraq War from the start. But he refuses to take responsibility for Congress’s — and his own — inaction on gun control.

At the Democratic debates last week in Detroit and two months ago in Miami, Sanders claimed he lost a 1988 race for Congress because he “ran on a platform” of banning assault rifles. It’s true that Sanders told Vermont gun groups in 1988 that he backed a ban on semiautomatic rifles — and that the NRA endorsed the Republican who beat him, Peter Smith. But there is little evidence to suggest that Sanders campaigned on the issue — or that it played much of a role in his loss. In fact, he told the Burlington Free Press that year that gun laws are “a local control issue” and should not be changed.

And while Sanders is quick to bring up his 1988 defeat, he rarely mentions his 1990 win, which came with help from the NRA. Soon after Smith took office, the freshman Republican reversed himself and sponsored a bill banning assault weapons. Vermont gun groups were apoplectic and called for his resignation. Throughout the 1990 campaign, Sanders deftly exploited the rift. Though he, too, supported an assault weapons ban, he promised hunters he would always be straight with them. That fall, the NRA spent between $18,000 and $20,000 on anti-Smith ads. “Bernie Sanders is a more honorable choice for Vermont sportsmen than Peter Smith,” NRA executive Wayne LaPierre wrote his members.

Sanders won the race and kept his promise. He was an occasional ally to the NRA, repeatedly voting against the Brady Bill, which mandated waiting periods and background checks; opposing funding for gun violence research; and voting to protect gun manufacturers and retailers from lawsuits.

He also honored his commitment, in 1994, to vote for an assault weapons ban. But as the frequency and severity of mass shootings increased over the next two decades, Sanders continued to maintain that the federal government ought to avoid regulating firearms. “In my view, decisions about gun control should be made as close to home as possible — at the state level,” he said after a July 2012 shooting at a movie theater in Aurora, Colo.

In my interview with Sanders after the Sandy Hook shooting, he said it was “more important” to address mental health than the availability of firearms, adding, “This is not one of my major issues.”

Sanders has since embraced federal gun control, and during his heated race against Hillary Clinton in 2016, he disavowed his previous positions on gun violence research and manufacturer liability. While the senator from Vermont isn’t the only rural Democrat who’s done an about-face on the issue, others have been more forthcoming about it.

Montana Gov. Steve Bullock (D) was an avowed gun-control opponent until last summer, when he declared his support for universal background checks and an assault weapons ban. During last week’s debate, he noted that he had been “personally impacted by gun violence” when his 11-year-old nephew was shot to death on a playground in 1994.

Sen. Kirsten Gillibrand (D-N.Y.) had an A rating from the NRA when she represented an upstate New York congressional district not far from Sanders’s. Soon after she was appointed to the Senate in 2009 — and inherited a far more urban constituency — she embraced gun control and earned an F rating from the NRA. “I didn’t do the right thing,” she told CNN this March, explaining that, earlier in her career, she had not cared enough about gun violence outside her district.

“I think that makes me a better candidate for president,” Gillibrand said of her willingness to reconsider her position. “I think it makes me a better person, because if you don't have an ounce of humility to know when you're wrong, how are you possibly going to govern all of America?"

That’s a question Sanders might ask himself.

Read more:

Katrina vanden Heuvel: Bernie Sanders’s bold ideas are transforming Democratic politics

George T. Conway III and Neal Katyal: It’s time to debate gun control on its merits

Megan McArdle: If conservatives want to keep their guns, they’re going to have to find a way to stop mass shootings

The Post’s View: No, Mr. Trump. Guns are the reason for mass shootings.

Leah Libresco: I used to think gun control was the answer. My research told me otherwise.