Coca-Cola marketing executive Wendy Clark's path to Hillary Clinton's presumptive presidential campaign might have started in Texas more than a decade ago.

Ms. Clark -- who recently took a leave for an expected role on Ms. Clinton's campaign -- was in the Lone Star State in the early 2000s where she worked at Austin-based ad agency GSD&M as director-client services. While there, she apparently formed a bond with GSD&M co-founder and Clinton confidant Roy Spence, who is also being mentioned for a potential Clinton campaign role.

Ms. Clark has described Mr. Spence as a mentor and shares his philosophy of "purpose-driven" marketing, signaling that the branding strategy could guide Ms. Clinton's campaign messaging.

Ms. Clark has not responded to email requests for interviews since announcing her leave of absence in early January. In a Jan. 9 internal memo to Coke employees, she said only that she was departing until March 31 for a "passion project" that was a "once-in-a-lifetime opportunity." Several people who are close to Ms. Clark declined to comment about her potential Clinton role.

But it has been widely speculated that Ms. Clark, a respected brand-marketing strategist who has also worked for AT&T, will help Ms. Clinton shape her campaign message. And she might do so alongside her mentor Mr. Spence.

In a recent blog post, The New York Times published what it called an "informal and wildly incomplete guide to the Clinton 2016 campaign," listing people who might serve on her team. Ms. Clark and Mr. Spence were listed as potential "message makers."

Mr. Spence's ties with Ms. Clinton are well-known and go back decades. As ABCnews.com noted in 2008, she met him while working on George McGovern's unscuccesful 1972 presidential campaign. She considers Mr. Spence as among "the best friends I've ever had," ABC noted, quoting Ms. Clinton's 2003 autobiography, "Living History."

Mr. Spence aided Ms. Clinton during her 2008 presidential run. He was brought aboard a few weeks before Ms. Clinton ran the famous "3 a.m." ad that aired during her hard-fought Democratic primary battle with Barack Obama. The ad set this scene: "There's a phone in the White House, and it's ringing. Something is happening in the world. Your vote will decide who answers that call." (Mr. Spence had original created the ad for the Walter Mondale campaign in 1984.)

Mr. Spence retired as CEO of GSD&M in 2009, but remains chairman. In ad circles he is best known for campaigns such as the "Don't Mess With Texas" anti-litter effort that launched in 1986. In 2008 he formed "The Purpose Institute," whose mission is to "put the power of purpose to work to build some of the most extraordinary brands in the world." In a speech at a 2013 event called "Conscious Capitalism," he described the lofty idea this way: "Play to your strength in the purpose of serving the greater good."

Should Ms. Clinton run, her purpose would be to leverage her strengths as an experienced political pro with a large base of female support, while crafting a message that appeals to a wide swath of Americans tired of politics-as-usual. Ms. Clark, a political outsider who has worked on mass-marketed brands, might bring valuable experience to the table in that endeavor.

Ms. Clark has apparently remained close to Mr. Spence. In a video interview posted on Makers.com she describes him as a "great mentor." The site launched in 2012 as a repository for interviews with groundbreaking women, including Ms. Clinton. The site suggests that Ms. Clark's upbringing was influential, noting that she was a "shy child who moved with her mother from England to Sarasota, Florida" and was "pushed out of her shell by the dramatic continental shift, and believes that's where the 'seed of fearlessness' began to grow."

In an interview on the site, she points to one lesson she says she learned from Mr. Spence: "You can be a better you, or a worse them. And that stands for branding. That stands for companies. That stands for individuals." She used the point to express frustration at women who try to act like men. "I love being a woman," she said. "I love being feminine and at the same time firm. I don't think you have to make a choice about that."

That mindset -- embracing who you are while playing to your strengths -- is the kind of ethos that might serve Ms. Clinton well as she tries to break the presidential glass ceiling (assuming she is running, which she has not yet formally announced).

While Ms. Clark's political resume is thin, she has been on the global stage while at Coca-Cola and developed a reputation as a digitally savvy marketer -- traits that Ms. Clinton might find attractive. Ms. Clark has championed social media; worked to appeal to millennials; and sought to appeal to moms who often control whether their families are drinking the company's juice and soda products. Also, she has pushed for marketers to combine owned, earned, shared and paid media, while putting social at the center of any plan.

"We know our target consumers -- teens and young adults -- are consuming media on multiple screens in single sessions. This means the TV is on, a laptop is open and a smartphone is in hand," she wrote in an op-ed published by Ad Age. "For marketers, this requires having a single, integrated conversation across those screens. When we do this well, we create significantly higher impact than any of those screens could do on their own."

Purposeful politics
During her time leading global marketing efforts, the company's far-flung marketers received accolades for various iterations of "Open Happiness." Indeed, Coca-Cola has looked to global ads for big North America marketing moments, such as the 2013 Super Bowl, when it aired "Security Camera," an ad that originated in Argentina.

Ms. Clark. just like her mentor Mr. Spence, is also a big fan of encouraging companies to embrace "purpose," rather than getting caught up in the day-to-day minutiae of selling packaged goods. Ms. Clark referenced Simon Sinek's TED Talk, "Start with Why," in an op-ed for Ad Age a year ago.

"For some, happiness can feel amorphous, ethereal, not direct enough of a link to our product. … Prolonged economic recession in many parts of the world makes us question, 'Can we really talk about happiness when so many are not happy?,' " she wrote. "In these moments, when we lead with the product (what) and not our mission (why), our decisions get smaller, our perspective less brave, our work less memorable, our world impact more limited."

Former Procter & Gamble Co. chief marketer Jim Stengel, who is an advocate for "purpose-driven" marketing, said the concept could work in politics. "Too many of our politicians who have not succeeded get yanked into tactics. And they just don't stay on their ideals," he said. He added: "I think the principles by which Coke manages its organization would be very helpful in a political campaign. And Wendy's been at the center of that. Just the idea that we are going to stand for something that's very inspiring. But then also how do we set up in a way to interact with people all the time around the world, and that is no small feat."

Coke connection
But Ms. Clark's Coke connection also carries negatives. The brand, after all, has been ridiculed by some health advocates for contributing to the nation's obesity epidemic. Still, Ms. Clark and Ms. Clinton are likely protected from broad-based attacks on that front, mostly because people accept that political campaigns have for a long time tapped corporate leaders, said Barbara O'Connor, emeritus professor of communications and director of the Institute for the Study of Politics and Media at California State University, Sacramento.

"I don't think the Coke image will necessarily be a negative for Hillary," she said. "I think [Wendy's] skill set is one that [Ms. Clinton] certainly would like to have, because Wendy is very well known and is excellent at marketing to Middle America. And that's a group that whoever is running for president needs to focus on turning out."

Contributing: Natalie Zmuda and Jack Neff