Sanguesa said he viewed it as "anti-white discrimination" - then got upset and lashed out.
The barista was later asked whether she denied service to Sanguesa. "No, I didn't," she responded, according to the Miami Herald.
Starbucks said in a statement to The Washington Post that "embracing diversity and treating each other with respect and dignity is core to Starbucks values and something our partners take great pride in showing. We are committed to providing an inclusive, supportive and safe work environment for everyone."
Jorge de Cárdenas said in an interview with the Miami New Times that he was telecommuting Wednesday from a Starbucks near the University of Miami when a customer became impatient while waiting for his drink and began screaming that he had been denied service because of "anti-white discrimination."
Another customer told Sanguesa he was an "a--hole" and Sanguesa said, "F-- you, b---," Cárdenas told the New Times.
Cárdenas then grabbed his cellphone and started filming the scene.
The video does not capture the moments leading up to the confrontation. But it does show Sanguesa demanding a refund.
"We want nothing to do with you," he told the barista, who appears to be a person of color. "You're trash."
"So what?" she replied.
"Because I voted for Trump! Trump! You lost! Now give me my money back," Sanguesa said, moving toward the register. "What is your name? I want your name. I want your card. You're garbage. You're complete trash."
No, the video was not staged. You cannot "stage" a sweater vest.
Another employee or a customer attempted to intervene.
"Don't talk like that to her," a man told him. "You want to talk like that, take it outside. But don't talk to other people like that."
"Don't tell me what to do," Sanguesa replied. "She did discrimination against whites."
The two men continued to argue and others chimed in.
Sanguesa quieted down for a moment, asking an employee whether he had heard how the barista had talked to him. "No, I didn't see that; I missed it," the employee said. "All I could hear was you."
"OK, fine!" Sanguesa shouted. "I'm going to punch you out."
"Want to step out?" the employee said. "Fine, I'll be happy to."
Sanguesa again demanded a refund. Then he walked toward the door, muttering that the situation was "absolutely ridiculous."
The Miami Herald reported that Sanguesa has a criminal history: In 2008, he was charged twice - one week apart - with DUIs. In 2014, he was charged with domestic violence, though that charge was later dropped, the Herald reported.
And for years, the Miami Herald said, Sanguesa has been emailing the newspaper "with rants against Cubans, women, immigrants, gays and lesbians, President Barack Obama and Hillary Clinton."
The newspaper reported:
In one email sent this month, he said Obama has caused 95 million people to lose their jobs by "pushing a sick, left wing agenda of not working . . . living off the government . . . trying to get rid of Jesus Christ, abortion, homosexuality, lesbians, transgender . . . Hollywood trash . . . we are Miami destroyed . . . by people who hate the USA."
Four days earlier he had sent an email about the coverage of the death of former Miami Marlins pitcher Jose Fernandez in a boating accident. "I hate Cubans . . . all pieces of s- including Jose Fernandez."
He ended the email: "Viva Fidel Castro!!"
Sanguesa told several news organizations that he has a mental illness, which he did not disclose, and that he had not taken his medication Wednesday - though he did not seem to blame the outburst on his condition.
"I had a bad day," he told the Herald on Thursday. "I was wrong for screaming at her. I have since apologized."
He has been adamant that his rant was not racist but was simply a response to discrimination from the barista.
In an interview with the New Times, Sanguesa said he was discriminated against because he supports Trump and worked on the president-elect's campaign - and is white.
"I was racially discriminated against," Sanguesa told the New Times. "This is bull---. I'm a business owner. I didn't deserve this. That woman refused to serve us coffee."
Sanguesa added that he was "wrong for getting upset" and that he had apologized to the barista, "but I'm not going to respond anymore. This is out of control. I'm being harassed by people all over the country."
