The third Republican presidential debate is just hours away, and most Americans are focused on the candidates themselves, rightfully so. However, often left out of the picture are those who provide an essential balance to the presidential hopefuls and know them best: their better halves. Here's a background on the wives of a few of the leading GOP presidential contenders, who will appear Wednesday at 8 p.m. EST on CNBC for the debate, broadcast from the Coors Events Center at the University of Colorado in Boulder.

Melania Knauss-Trump


 

If front-runner and billionaire real estate mogul Donald Trump takes the White House in 2016, his 45-year-old wife Melania Knauss-Trump would become the first foreign-born first lady since Louisa Adams, wife of sixth U.S. President John Quincy Adams.

She would also be the only first lady to have worked as an international supermodel and to have posed nude, lying on a fur blanket handcuffed to a leather briefcase aboard Donald's jet for British GQ in 2000, before they were married. That same year, she told Howard Stern that her and Donald "have incredible sex at least once a day...sometimes even more." The Donald, of course, boasted about how sexy Melania looked in "a very small thong," according to the New York Post.

Melania's fairy-tale life began in Slovenia on April 26, 1970, when it was still part of Yugoslavia, and she grew up in one of the nondescript concrete apartment buildings under the rule of socialist Josip Tito, according to The Washington Post.

Her father, an Austrian businessman named Viktor Knavs, managed a chain of car and motorcycle dealerships, and her mother, Slovenian-born Amalija, was either a fashion designer or a garment factory worker, depending on who you ask.

"My mom was in the fashion business. I was 5 years old when I did my first catwalk and did commercials at 16," Melania told the website Parenting a few years ago. "I went professional after my studies. My mom loved fashion. We loved to travel and go to Italy and Paris."

Melania, a well-mannered and shy teen, went on to study architecture and design at the University of Ljubljana in Slovenia, and at age 18, she signed on to a modeling agency in Milan, Italy, subsequently appearing on the European editions of Vogue, according to the Daily Mail.

The 5-foot-11, 35-24-35 model relocated to New York City in 1996 as a determined and career-minded homebody, where her picture soon appeared on a Camel cigarettes billboard in Times Square, and she began posing in catalogs of upscale stores like Lord & Taylor. Before long, she was gracing the cover's of the biggest magazine's around: Harper's Bazaar, In Style, Vanity Fair, Elle, and perhaps most notably, the 2000 Sports Illustrated swimsuit edition.

Melania first met Donald at a party in 1998, one year after he had separated from his second wife, and the rest was history.

"I saw Melania and I said, 'Who is that?'" Donald recalled to People. "She was a very successful model. She was terrific. I tried to get her number, and she wouldn't give it to me."

"He came to the party with a date!" Melania explained in her heavily accented English, laughing. "I had heard he was a ladies' man, and so I said, 'I'm not one of the ladies.' He said later that he sent her to the ladies' room so he could get my number. I was like, 'Oh what a sneaky way!'"

Melania said it was Donald's "sparkle" that caught her eye, so she took his number and called him after returning from a modeling job in the Caribbean.

The two wed in a lavish ceremony at Donald's Florida Mar-a-Lago estate in 2005, with Melania sporting a $200,000 Christian Dior dress.

Since then, Melania has become quite close with Donald's four children from his previous marriages, and in 2006, birthed Donald's fifth child, Barron Trump, now 9 years old. She became an American citizen the same year.

More recently, Melania, who speaks three other languages (Slovenian, French and German), started her own line of personally-designed jewelry, Melania Timepieces & Jewelry, and a skin care line, Melania Beauty, marketing a $150-an-ounce moisturizer made with caviar.

But when it comes to the political arena, the unconventional spouse of an even more unconventional presidential candidate typically shies away from the spotlight and has rarely been seen alongside Donald on the campaign trail.

"My husband is traveling all the time," she told People. "[I was] not ready to get political yet."

"Barron needs somebody as a parent, so I am with him all the time...I like to be hands-on. I think it's very important," Melania said, explaining that she prefers to avoid relying on help from a traditional nanny.

Roger Stone, Donald's former political adviser who has known the couple since before they were married, told the Post that Melania "provides great balance" to Donald and is smart, "not just an armpiece."

"She would be the most glamorous first lady since Jackie Kennedy," he added.

Lacena "Candy" Carson


 

Candy Carson is the 62-year-old wife of retired neurosurgeon Ben Carson, who has soared to second place in an average of polls following his performance in the second GOP debate and finally overtook Trump in a national poll Tuesday, ending the real estate mogul's 100-day reign as the continuous front-runner.

Lacena "Candy" Rustin was born in Detroit and grew up in the inner city with five siblings. The daughter of a factory worker and a teacher, Candy says she "grew up poor," according to The Hill. Despite tough economic hardships as a child, like Ben, Candy excelled, studying classical violin and winning a scholarship to Yale University, where she met Ben in 1971. She triple-majored in music, medicine and psychology, and she played in the Yale Symphony Orchestra and the Bach Society.

They married in 1975 upon Candy's graduation and moved to Baltimore, where Candy received her master's of business administration from Johns Hopkins University and "arranged and conducted for several groups including the University of Maryland Medical Center Chamber Players," according to the National Review.

The two went on to have three now-adult sons: Murray, Benjamin Jr., and Rhoeyce, who Candy stayed at home to raise while Ben was working long hours as the director of Pediatric Neurosurgery at Johns Hopkins Hospital in Maryland, where he remained from 1984 until his retirement in 2013.

Speaking to Fox News' Megyn Kelly earlier this month, Candy said she "sometimes felt like a single mom because he wasn't around most of the time."

"It was busy - but we made time for family as much as we could," Candy told Breitbart. "You know that when he was away, he was saving lives," she explained.

Candy, a devout Christian, said the key to sustaining their 40-plus year marriage in the modern world has been her faith. "A family that prays together, stays together," she maintains.

In 1994, Candy, with the help of Ben, co-founded the Carson Scholars Fund, a nonprofit that initially awarded one scholarship to a student in each Maryland country. Now, the fund awards scholarships in 50 states and the District of Columbia, with recipients being young people who display high academic achievement and stellar character.

She also helped Ben write the bestselling book, "A More Perfect Union: What We the People Can Do to Reclaim Our Constitutional Liberties," which was published this month. Candy had a hand in writing "One Vote: Make Your Voice Heard," and "One Nation: What We Can All Do to Save America's Future," both published in 2014, as well as "America the Beautiful: Rediscovering What Made This Nation Great" from 2012.

Coping with her husband's decision to run for president has been tough for Candy, who told Kelly that while she plans to give 100 percent of her support to Ben as he runs for president, "This is not something that I was looking to do. After giving up my husband for 40 years to medicine, I really don't want to give him up to our country."

But Candy changed her mind after having grandchildren and considering that they might not have a future if "we don't start thinking about what's going on in this country," Ben previously said in an interview when he was still testing the presidential waters, according to Breitbart.

Unlike spouses of many other candidates, Candy, with an outgoing and bubbly personality that has been compared to Michelle Obama, eventually jumped into the political world right along with her husband, hitting the campaign trail and even campaigning on her own.

For example, Candy played the violin at New Hampshire's Grace Capital Church - the state's version of a megachurch - where she led a sing-along to "He's Got the Whole World in His Hands" and "How Great Thou Art," according to The International Business Times. She also helped Ben kick off his 2016 bid by playing the violin with a gospel choir as they performed a joyful rendition of "The Star-Spangled Banner." She seems to enjoy the spotlight to a certain extent, giving a number of recent interviews, including one on "The View," and trying to explain her soft-spoken husband to the public.

The two even celebrated their 40th wedding anniversary on the campaign trail in New Hampshire along with "600 of [their] closest friends," noted the Daily Mail.

As first lady, many expect Candy would focus on education, and her and Ben's strong evangelical faith as Seventh-day Adventists would likely put those concerned with separation of church and state on the edge of their seats, according to The Hill. But Candy says whether or not that day ever comes is "up to God."

Jeanette Dousdebes Rubio


 

Jeanette Dousdebes Rubio, the wife of Florida Sen. Marco Rubio and a former Miami Dolphins cheerleader, went to South Miami High School in Florida with the presidential contender, but they didn't meet until she was 17 and Marco was 19, according to the Tampa Bay Times.

"I was at the (West Miami Recreation Center) one day playing volleyball and he spotted me," Jeanette told the Times in 2012. "So he asked questions and friends put something together where we would go to the movies and he would sit next to me and then - you know, coincidentally. Throughout the whole movie he would start talking to me, which I thought was a little annoying."

The relationship was disrupted as Marco went off to college at the University of Florida, and the two tried long distance for awhile.

In his statesman-like fashion, Marco wrote "these really long letters" to Jeanette expressing how hard it was "for me to even stay up there on the weekends, just because I wanted to be back [with Jeanette]," he told the Times.

"One of the letters that he wrote to me, I still have it," Jeanette said. "It was about how we were building a foundation and we were going through the steps. And he wrote all the steps in comparison to where we were in our relationship."

While Marco was attending law school at the University of Miami, Jeanette studied at Miami-Dade Community College, worked part-time as a bank teller, and was also a cheerleader for the Miami Dolphins in the mid-1990s, where she was featured in the cheerleading squad's first swimsuit calendar before leaving the team in 1996.

The couple dated on and off for several years and got married as soon as Marco finished law school, on a trip to New York City in 1998, where Marco popped the question from the top of the Empire State Building in honor of her favorite movie at the time, "Sleepless in Seattle," according to ABC News.

Soon after, Jeanette, the daughter of Colombian immigrants, gave birth to their first child, Amanda, who is now 14 years old, and eventually had three more children, Anthony, Daniella and Dominic.

Jeanette told Parade Magazine in 2013 that she loves being a mom and that her Christian faith is very important to her. "And I'm very involved - you know, with the time I have in between the kids and my job-in the issue of human trafficking," she said. "There's a local organization called Kristi's House that they started for kids who were abused and then got involved in human trafficking."

As of April, Jeanette was taking care of the children in their Miami home while working part-time at the family foundation of Miami billionaire Norman Braman, helping to manage millions of dollars in donations to nonprofits and charities, according to The Washington Post. Braman has said that he'll donate at least $10 million to help Marco during his campaign.

Jeanette has described herself as shy and historically shied away from the spotlight during Marco's political career, including his Senate campaign, but she did tell the Times in 2012 that she enjoys campaigning. "You meet a lot of different people and you hear their stories," she said.

However, Jeanette described the mudslinging associated with political campaigns as particularly disdainful. "The part that's difficult, I think, in campaigning is the part where you have to deal with the negativity that comes," she said. "It puts a lot of strain on the family."

"I'm not pushing myself out there. I need to be with (the) kids just to give them that balance," she added. "If he's out there, I feel like I have to be here for them, to give them that reality."

She also said that she will "of course" be more involved in Marco's political career in the future, should he continue his rise in the polls and win the nomination. "In the future, if I have to do it, of course I'll do it. But in general, I am shy."

"I've also just never been in a position where she's had to give stump speeches or do things of that nature. It just hasn't been what we do," she said.

Heidi Nelson Cruz

On the campaign trail, Tea Party favorite Texas Sen. Ted Cruz often brags about his wife, Heidi Nelson Cruz. Not only is she "beautiful, brilliant" and his "very best friend in the whole wide world," he says, but she's also the best fundraiser on his team, according to CNN.

Perhaps the most involved wife of any GOP contender, 42-year-old Heidi took an unpaid break from working as an executive at Goldman Sachs to help out at the senator's presidential campaign headquarters, where she is now effectively heading his fundraising operations.

"She works the phones the way she worked them when she was at Goldman," Chad Sweet, Ted's campaign's chairman, told CNN. "There are very few spouses who can get on the phone on a cold call to a prospective donor and make a more compelling case in a personal and effective way than Heidi Cruz."

The polished business executive was born in San Luis Obispo, Calif., to parents who were Seventh-day Adventist missionaries. She spent part of her youth in Nigeria and Kenya along with her brother, providing charity dental work with their father, a dentist with a practice in her hometown, according to The New York Times.

"I think those early travels made me expansive in terms of the things I wanted to do," Heidi said.

Her life was rigidly structured from an early age, waking up at 5 a.m., reading her bible, practicing piano and going to school, according to the San Luis Obispo Tribune.

With that structure came a strong work ethic that provided lasting life lessons. Heidi's parents helped her and her brother set up a bread-making business at a young age, and by the time she was 6 years old, Heidi was earning $150 per week, money that she eventually used to buy a car and help pay for college.

"I think it definitely taught us the value of hard work. We were used to being highly productive at all times. We got kind of competitive with each other. We probably made 200 loaves a week," she said.

She went on to obtain an economics and international relations degree from Claremont McKenna College and an MBA from Harvard.

In 2000, she met Ted in Austin, Texas, where the two served as policy aides on former President George W. Bush's presidential campaign. Five months later, in May 2001, they were married.

After Bush was elected, she worked as the director for the Western Hemisphere at the National Security Council from 2003 to 2004 and then moved back to Houston, Texas so her husband could pursue elective office in Texas. In 2005, she joined Goldman Sachs and currently lives in Houston with the couple's two young children.

"I think it works really well for our family for us both to have careers, and I know what my commitments are to Goldman," Heidi told the Times. "I think it's also really good for our girls to have me at home with them."

Heidi, a vegetarian and Christian, spoke in 2009 about being raised to help others, saying, "It's ingrained in our family that life is about giving back."

After Ted was elected to the Senate and gained notoriety for helping force a government shutdown over his opposition to President Obama's signature health care law, Heidi says her faith helped her get through the harsh criticism and death threats, according to Heavy. It also helped her cope with a bout of depression after leaving her White House job and moving back to Houston.

A family friend from Texas said that Heidi "brings more to the table than any other spouse in the field, except for maybe Bill Clinton, and she does so without the baggage of a Bill Clinton," reported The National Review.

Another friend, David Panton, told the Review: "Heidi is a secret weapon because she is so warm and so endearing and so thoughtful that I think that her influence on him has been transformative; he would not have been a senator were it not for Heidi and for her role and her support."