In Cuban Miami, the past is never too far away.

One of the most poignant stories my mother tells about our lives in 1960s Cuba begins with her standing at the bread line in the neighborhood bodega of our lovely seaside Matanzas.

Every family was allowed, per the ration book, one quarter piece of bread per member. We were four: my mother, father, brother and I, and that’s how the grocer proceeded to fill the order.

But a woman came out of her place in line and stopped him. My mother was only entitled to three pieces, she argued, because my father had been sent to work in the agricultural fields as punishment for declaring his intention to leave the country. He was not at home to eat the bread.

The woman demanded that the grocer take away his share, or she would report him to the Committee for the Defense of the Revolution for being a friend of traitors.

In those small, dehumanizing moments and with the complicity of neighbors — people who had known you all your life — Fidel Castro solidified his grip on power. Through repeat performances — different decades, new supporting characters, same methods — he and his brother Raúl sustained their dynastic dictatorship.

I can barely stand to hear my mother tell the bread story without a terrible sense of hopelessness taking hold — and now, in the midst of hopeful change, a disgraceful video out of Havana brings back that feeling with wicked force. Circulating in Miami and the Cuban diaspora, the video shows a group of Ladies in White last month shouting epithets and staging an acto de repudio, an act of repudiation, against one of the group’s founding members, now an outcast.

“Traitor, traitor,” they yelled. “We don’t want to listen to you.”

The loathsome behavior by otherwise brave Damas de Blanco, so lovingly hosted at the Freedom Tower and welcomed in Miami, is what you’d call the work of the devil himself. Or, perhaps, it’s only another instance of that national character flaw that filmmaker Néstor Almendros so perfectly defined as “the Fidelito we all carry inside of us.”

Like so many here, I’m struggling to understand why leader Berta Soler would ever allow, much less encourage, the vulgar and angry protest against the presence of founding member Alejandrina García de la Riva at the Ladies’ headquarters, the home of the late founder Laura Pollán. Soler acknowledges that she had a falling out with García over the direction of the group. Others say the breakup was over things like money.

Either way, Soler voices little regret for the acto de repudio nor offers an apology.

How sad.

These valiant women won the world’s respect for their peaceful silent marches in Havana, armed with nothing but gladioli and human rights principles to prove that their dissident husbands, fathers, sons and brothers didn’t belong in prison.

Their disintegration is heartbreaking.

There’s no presidential decree, no bilateral agreement, no thaw that will ever change Cuba for the better until the undignified fight for that metaphorical piece of bread ends. In a country with an unsavory history and a frail future, the last thing dissidents need is to fight each other using the appalling methods of the dictatorship.

It’s as if intolerance is our only destiny, the past never a lesson, always lurking, ready for a return.

When I wearily called my mother Tuesday as I was writing this, she didn’t hesitate to re-tell me her story of the woman who tried to take away a piece of bread in the name of the Revolution.

“Oh yes, Carmen. She was my best friend,” my mother said. They went to parties and places together before the revolution, the only one of her friends my grandmother trusted.

And I realized then that I had exiled their friendship from my memory of the bread story, severed it, as if by doing so, I could take the sting out of the despicable — for all of us.