At least one potential U.S. presidential candidate thinks cryptocurrencies might be widely used in the future.

Starbucks chairman emeritus and former CEO Howard Schultz, who announced Sunday that he was considering making a run for the highest office in the U.S., has previously said that he sees cryptocurrencies as a future part of a cashless, digital economy, though he did not see bitcoin as a "legitimate" cryptocurrency.

The former CEO of the popular coffee chain discussed cryptocurrencies and blockchain during a quarterly earnings conference call in January 2018, telling investors that while he does not see bitcoin becoming a widely-used currency, he does think the underlying blockchain technology had numerous potential uses, in particular with helping his company transition to new payment models.

Schultz went so far at the time as to mention that cryptocurrencies would be incorporated into the company's long-term digital payments strategy.

"I'm talking about ... the possibility of what could happen — not in the near term, but in a few years from now — with a consumer application in which there's trust and legitimacy with regard to a digital currency," he said, adding:

More recently, his company appears to have warmed even to bitcoin. As revealed last summer, Starbucks has been working with Intercontinental Exchange, the parent of the New York Stock Exchange, on Bakkt, the upcoming bitcoin futures exchange. The retailer will help develop "practical" applications to convert digital assets into U.S. dollars at the point of sale, the companies said at the time.

Schultz, who announced he was "considering" a run as an independent centrist candidate on Sunday, has also written a new book, which was released Monday.

Without mentioning the book, he said in a video posted Monday that he would soon embark on a "listening and learning" tour of the U.S.

"In the next few weeks and few months, I'll be traveling the country. I'll be listening, and learning, and meeting many of you," he said. "I look forward to seeing you and I strongly believe that this is an opportunity in America at a very fragile time, to embrace a better choice, not the status quo which will lead to decline, but a better choice that I think will lead to a season of renewal, leadership that you can trust and once again government that can be working for all the people."

Schultz did not immediately respond to a request for comment.

Howard Schultz, left, image via Chairman of the Joint Chiefs of Staff from Washington D.C, United States / Wikimedia Commons