click to enlarge File: Matthew Thorsen

It's exasperating to watch: Sen. Bernie Sanders onstage at the Netroots Nation convention in Phoenix, Ariz., doggedly sticking to his script while the chants rise from the audience. "Black lives matter!" "Say her name!"

"Should I ... Do I have..." he fumfers, conferring sotto voce with the moderator, journalist and documentarian Jose Antonio Vargas. Finally Sanders turns to the audience. "Let me talk about what I'm going to talk about for a second." The shouts grow louder. "Here's the serious issue. We live in a nation in which to a significant degree the media is controlled by large multinational..."

From the floor: "SAY HER NAME! SAY HER NAME!" The phrase refers to the movement to confront police-inflicted rapes, beatings and deaths of hundreds of women of color — six dead in 2015 alone.

"I want to give you some bad news and some good news."

The room vibrates with frustration. Vargas tries to steer Sanders toward addressing it. He doesn't.

Exasperating, and classic Bernie: man of the people treating the people like tiresome children, telling them what the issue is, instead of listening to what their issue, our issue, America's issue, is right now. The event took place a week after another black person, Sandra Bland, was arrested, brutalized, jailed and either killed or allowed to die in custody — for failure to signal a lane change.

Yeah, Vargas told In These Times later, Sanders "was a little tone-deaf." Neither he nor the other Democratic candidate at the forum, former Maryland governor Martin O'Malley, could hear "the humanity and the urgency" in the protesters' voices. Some of the women were crying.

But Sanders' performance didn't just betray his social cluelessness. His cluelessness is ideological. Old New Leftists had a name for it: "vulgar Marxism." A vulgar Marxist is a guy (and they're pretty much all white guys) for whom there is one explanation and one explanation only for everything wrong with the world — indeed, for everything in the world: economic class.

I'm not arguing that Sanders is wrong to say that extreme income inequality is a fundamental issue. Or that, as he frequently points out, in the scheme of economic injustice, people of color are the worst off. I have no beef with his record. Sanders gets a 100 percent rating from the NAACP, and NARAL, every year. When he was mayor of Burlington, I'm told, he marched in the gay pride parade.

Still, these things are secondary to him. "He is not a rainbow-coalition guy, or at least he hasn't been," Greg Guma, author of The People's Republic: Vermont and the Sanders Revolution, told CNN. "He feels like he knows what the problem is, and it's monopoly capitalism. Anything that takes him away from that message is a distraction."

Anything and anyone. "Let me ask you," Sanders said to National Journal reporter Simon van Zuylen-Wood in 2014, "what is the largest voting bloc in America? Is it gay people? No. Is it African Americans? No. Hispanics? No. What?" The senator answered his own question: "White working-class people."

To win elections, then, or to spark the "political revolution" Sanders has been fomenting from the stump, the trick is to lure true-blue American blue-collar white people back from the wilderness they're wandering in. It's precisely the opposite of the strategy that twice won Barack Obama the presidency.

So now his handlers are getting it: If Sanders wants to "win minority votes," he'd better start courting a wider demographic.

But let's get real. Sanders says he's in it to win, but everyone knows — or assumes — he won't. His role is to change the political conversation. How does he intend to change it? By rewinding it 50 years, to pure bread and butter. The vulgar part is that he is doing this just when white progressives are beginning to catch up with what black, brown and native peoples have known forever: American history — its justice and injustice, and therefore its politics — is enacted on the body differentially depending on the body's color and gender, its age and ability, and its place of birth.

Bland was a college graduate with a late-model car and a middle-class job. But because her body was black, no amount of economic opportunity could protect her. Politics neither begin nor end at the pocketbook.

At Netroots, Sanders finally answered the cries from the floor. "Black lives of course matter," he said — with that "of course" dismissing the urgency of the call in the same breath as he acknowledged it. Then he returned to his talking points.

Unsatisfied, the audience persisted. Sanders started to leave the stage. "I spent 50 years of my life fighting for civil rights and dignity," he muttered. "But if you don't want me to be here, that's OK."

Like the white liberals expelled from the civil rights movement when black power supplanted nonviolent civil disobedience, like the men in the '60s Left confronted by angry women, Bernie felt wounded. It was as if he were the one being disrespected.

He is trying to clean up his act. The night of the Netroots debacle, he attended a fundraiser for the Democratic donors' advocacy group Latino Victory Project and talked about race. "I want your ideas," he said, almost humbly. "What do you think we can do? What can we do?" It was hard to tell whether his newfound willingness to listen was mostly optics.

Writing on VTDigger.org, Curtiss Reed Jr., executive director of Vermont Partnership for Fairness and Diversity, took Sanders at his word. Reed congratulated the senator on moving from the ranks of the "unconsciously unskillful" to those of the "consciously unskillful" and offered advice on how to become "consciously skillful" about race. The first thing would be to stop referring to Vermont as the whitest state in the nation and notice that people of color have been living here since the 17th century. Reed also suggested that Sanders meet "personally and frequently" with people of color, their organizations and white allies.

In Phoenix, Tia Oso, national coordinator for the Black Immigration Network, who took the stage during O'Malley's interview, told a CNN reporter she hoped the candidates were now ready to talk and "build their platforms" with communities of color. "They have a lot of homework to do," she said, smiling.

A message tweeted from Sanders' account shortly thereafter confirmed Oso's impression: "I will #SayHerName," it said. "Sandra Bland, Eric Garner, Freddie Gray and too many others."

Race: check. Gender? Oops. After 40 years of not exactly paying attention to these things (that 1972 rape-fantasy essay in Vermont Freeman may have been his last try), Sanders is unlikely to be a quick study.

For the record, here are a few names of police-murdered women of color: Eleanor Bumpurs, Tyisha Miller, LaTanya Haggerty, Kayla Moore, Mya Hall, Alexia Christian, Gabriella Nevarez, Aura Rosser. There are indeed too many others.

But perhaps it's unfair to single out Bernie Sanders for condemnation. If he's clueless, what about the rest of the presidential candidates? Once Barack Obama leaves the White House, will any of its potential occupants say those names, see those faces? Will they even try to imagine the impact of fist, club or bullet against vulnerable human flesh?