Sanchez says she feels “a strong commitment to freedom, so someone might think, ‘Aha! A liberal.’ But I’m also worried about the poor. I come from a very humble background, very poor. . . . Some people tag me as a communist or a leftist.”

Her father is a train operator and her mother also works.

She opposes the U.S. economic embargo of Cuba, saying it is the pretext on which the Castro regime blames all failures. But she says she has many friends who favor the embargo, and the underlying beliefs that bind them are the longing for freedom for Cuba. The real embargo, she said, is of the civil rights of Cubans.

“I identify myself as a free electron. I gravitate or associate with the nuclei or atoms depending on the strength of their premises,” Sanchez said.

It is a critical posture that has earned her enmity not only from the Cuban government but also of Latin American leftists clinging to hopes of Cuba as an ideological beacon. They accuse her of being a puppet of outside powers, a mercenary. She rejects the charge.

Last month in both Recife and Salvador, Brazil, militants arrived at airports to protest her presence. Elsewhere, leftists have lashed out at her in the media.

On Sunday, some 30 noisy protesters gathered outside the Puebla hotel where she was speaking to a hemispheric group of newspaper publishers. They held up a banner that said “Viva Fidel” and broke past security in an effort to disrupt her news conference.

At the conference, Sanchez spelled out how she believes Cuba is a “geographic prison,” where holding any variant opinion risks jail and where only one loud voice is allowed on state-controlled media.

Microphones are needed for all the other voices on the island, she says, voicing optimism that “very talented Cubans” are well-prepared for the day a democratic transition arrives.

She reiterated that she would return to the island when her trip ends, even if she must do so as a “reverse rafter,” sneaking back into the country, with the aim of starting an independent news outlet that goes beyond blogging.

“I know that this is impossible and that legally it is prohibited. But I won’t be the one putting up these boundaries. Life has taught me that the wall comes tumbling down only when you push it,” she said.

Sanchez estimated that only some 120 “alternative” Twitter users are sending tweets describing island life, constrained by barriers and costs. Using a computer at a tourist hotel can cost $6 to $10 an hour, up to half a month’s salary for ordinary Cubans. Some of those who get past this burden do so thanks to supporters abroad who put credit on their mobile phone accounts.

“Recharging a cellphone in this way turns a person into a possible transmitter, a source of information and news, thanks to the solidarity of many people,” she said. “With a little ingenuity, with lots of difficulties, you can narrate (life on) the island in 140 characters.”

Cuban exiles arriving back for family visits and foreign tourists leave behind mobile phones, flash drives and used laptop computers, she said.

“Climb aboard one of our collective taxis in Havana _ maybe a 1954 Chevrolet _ and amid the noise of a vehicle at the point of collapse, the potholes in the road, the facades of buildings that seem like they are trapped in the past, suddenly a person will pull an iPhone 4 from their pocket,” she said.

Even if tourism has brought a boom in prostitution, she added that “it is also true that it has brought whiffs of freedom.”

She’s heard the rumors that maybe the Castro regime will bar her return. At the least, she expects “an execution by the media, a public stoning . . . stigmatizing of my image, demonizing me.”

“But I’m willing to accept this cost,” she said. The insults, she added, remind her of a saying by Cuban national hero and poet Jose Marti, who said, “To honor, brings honor.”

“I would say that, ‘to insult, brings insults,’ and to the persons who hurl insults, these insults will turn around like a boomerang against them,” she said.