Earlier this week, Sen. Bernie Sanders (I-Vt.) spoke of marching with the Rev. Martin Luther King Jr. It was a testament, he said, to his long history advocating for people of color.

That comment didn’t go over so well with many of the women of color in the audience.

“I was actually at the March on Washington with Dr. King back in 1963, and — as somebody who actively supported Jesse Jackson’s campaign, as one of the few white elected officials to do so in ’88 — I have dedicated my life to the fight against racism and sexism and discrimination of all forms,” Sanders said at a She the People event in Houston.

There were audible groans from the audience. Sanders responded by wagging his finger at the crowd.

The Post reported:

Before an audience of about 1,700, many of them African American and Hispanic women, the moderator asked Sanders (I-Vt.) how he would handle the rise in white supremacy. Sanders spoke of fighting discrimination and running a campaign “to bring our people together around an agenda that speaks to all people” — then returned to a familiar message on universal health care.

For many in the audience, that was insufficient. “Come on!” a woman shouted from the back, as others began to jeer and boo.

Later, former Ohio state lawmaker Nina Turner, the most high-profile woman of color on the Sanders campaign, referred to the audience’s reaction, asking “in what world” was it appropriate for the conference attendees to boo Sanders for sharing his story of protesting with King.

Sanders’s finger wag — and Turner’s talk — suggest the Sanders campaign may continue to struggle to draw in voters of color.

By focusing on a 50-year-old anecdote, Sanders missed a key opportunity to explain what he’s done for women of color in the past 10 years and how he’d tackle today’s challenges. And when listeners expressed their frustration, Sanders seemed dismissive and unwilling to engage. The optics of a predominantly white crowd applauding Turner for chastising women of color only fueled this message more.

Sanders struggled to attract voters of color during the 2016 Democratic primary. This time around, he’s acknowledged that he must do better. He’s met with black leaders and offered increasingly specific solutions for how he will improve the lives of people of color, who often face greater challenges than the overall population. There’s some evidence that’s working. According to a Monmouth University poll released Tuesday, 27 percent of nonwhite voters prefer Sanders to the other Democratic candidates. Former vice president Joe Biden came in second with 25 percent. Sen. Kamala D. Harris (Calif.) placed third.

But these numbers don’t mean that much right now — especially since more than 1 in 5 voters (21 percent) said they aren’t sure which candidate they prefer. And in the largest Democratic field in recent history, which also includes two high-profile black senators, it will take a sustained effort.

In this campaign, Sanders has an opportunity to do better with minority voters. Pushing back on voters who express concern is not likely to win Sanders more support from constituencies he needs to capture the Democratic nomination.