The prospect of a well-funded, third-party candidate could have a significant impact in a race where Trump is expected to be unable to win a majority of the vote. In 2016, Trump won just 46% against Hillary Clinton and has consistently hovered below 50% in national polls.

A source familiar with Stack’s thinking said, “Mr. Stack enjoys running Dick's Sporting Goods and has no plans to run for any elected office.”

The message testing told a different story. Those in the group were shown several short videos of other candidates including Biden, Warren and former Starbucks CEO Howard Schultz — a fellow billionaire who explored a presidential bid as an independent before announcing in September that he would not run — but viewed eight or nine videos that included Stack messaging, according to a focus group participant.

The focus group member, who presented paperwork to verify participation, declined to be named.

Among the questions posed to the roughly two dozen participants: ‘would you be open to voting for a third party candidate?’”

Not all the feedback was positive for Stack, who is 64.

“[Focus group members] mentioned that if Biden’s getting the criticism that he looked old, Ed Stack didn’t look young either,” the participant said, adding that some felt Stack “didn’t have the charisma it would take to attract a coalition that you’d need to have a chance as a third-party candidate.”

The session concluded with participants asked to vote on sample ballots that matched up Stack, Biden and Donald Trump and then Stack, Elizabeth Warren or Trump.

Stack has taken on a higher media profile in recent weeks, coinciding with the release of a new book, titled “It’s How We Play the Game.” This week, Stack took aim at Senate Majority Leader Mitch McConnell for failing to make headway on gun reform.

"I wish he'd have the guts to bring it to a vote," Stack said.

Joe Hunter, an adviser to Gary Johnson’s Libertarian Party presidential bids in 2012 and 2016 said he has heard Stack’s “name come up” in discussions about a possible run for president.

But he cautioned about the uphill battle of landing on state ballots for any third party candidate.

“It’s massive; all the structural, institutional barriers are really, really difficult … Absent having extraordinary resources, it would be difficult to put it together.”

But Stack would begin with some advantages, including his personal wealth and the national attention he captured last year after announcing Dick’s Sporting Goods would destroy $5 million of assault-style weapons and alter its gun sales policies in the wake of the Parkland high school shooting. Stack won accolades for his decision but also faced a backlash, including from the NRA.

While Stack is testing as an independent candidate, he has been a major Republican donor. In 2012, he gave $100,000 to Restore Our Future, the super PAC backing Mitt Romney. He’s also given $10,000 to the Pennsylvania Republican Committee and donated to various GOP congressman, including House Minority Leader Kevin McCarthy.

In 2016, he drew the ire of the National Republican Congressional Committee after donating $300,000 to a super PAC supporting House Democrats — a donation he said at the time was aimed to benefit his sister, Kim Myers, who was running for Congress as a Democrat in New York.

“Edward Stack is funneling hundreds of thousands of dollars into Nancy Pelosi’s Super PAC to fund his kid sister’s campaign for Congress,” the NRCC said at the time. “It’s nice to see that Stack is using the money he’s made off of his family shipping jobs out of Upstate New York overseas to China to try buying Kim Myers a seat in Congress.”

At a recent event to promote his new book, Stack referenced a meeting with Parkland parents.

“One of the things I asked the parents from Parkland as we were leaving was, ‘What is it that you would like me to do?’ They said, ‘We would like you to keep the conversation going,’” he said in Binghamton, New York, where he grew up. “That was a big watershed moment and we need to keep this conversation going. Which is one of the reasons I wrote the book. It talks about all the things you did to build the business to be in a position to be able to make these kinds of differences. One of the reasons to write the book was the commitment to those families to keep it going.”