If Indiana Gov. Mitch Daniels and Mississippi Gov. Haley Barbour had their way, they might have entered the GOP presidential campaign months ago. Their spouses had too many reservations, however, so the would-be candidates never left their statehouse steps.

Even New Jersey Gov. Chris Christie, who is reportedly reconsidering a run for the Republican nomination, has said “my wife would kill me” if he got in the race.  But not all spouses are so resistant, with Mitt Romney’s wife, Ann, attempting to woo voters on the campaign trail and Texas Gov. Rick Perry’s wife, Anita, promising a better prepared debater the next time her husband takes the stage.

Ann Romney

The former Massachusetts governor is often called robotic by his critics, but his wife is the complete opposite: warm and, thanks to her charm and some serious health struggles, down to earth, easily connecting to voters.

Romney stumped for her husband this weekend in South Carolina, sharing personal stories about her multiple sclerosis diagnosis and getting laughs, telling the crowd, “If they don’t pick Mitt, that’s their stupid mistake, not mine.”

She’s headed to the first caucus state of Iowa this week for the first time this cycle, holding events and fundraisers for local candidates, while also stumping for her husband. Iowa campaign consultant for the Romney campaign David Kochel says Ann Romney still has “many, many friends” in Iowa from the previous campaign and calls her a “tremendous asset to the campaign in every aspect.”

“In some ways, she is a secret weapon, but I don’t think it’s that secret if you know her or know them as a couple,” Kochel said. “She’s just a tremendous resource for the campaign because of the way she can connect with people. Her own personal story and how she opens a window into him and how he thinks and makes decisions.”

Romney has the advantage of this being her second time being out on the presidential campaign trail and in South Carolina she mentioned that she has had a “totally different mental change” from the previous campaign, saying she was “worried all the time” during the that race. This time, she’s not worried, knowing “Mitt’s going to win.”

A campaign adviser who says Romney is “extraordinary popular wherever she goes” says both Romneys are more comfortable this time around and they are both “enjoying it more.”

“They are a great team. The more people get to know the family, the team, the better off the governor is,” the adviser said of Ann Romney and their five sons. “She brings a personal side, a personal view of the governor that a lot of folks don’t know or don’t see. … She expresses it in a way with voters.”

The adviser said they are still developing a strategy for where Ann Romney will campaign for her husband but “mostly where he’s not. When she’s out on her own, it will be places where we think is important.”

She also will be doing more finance events for the campaign.

While campaigning in the Palmetto State this past weekend, she stayed in the governor’s mansion with Gov. Nikki Haley. The same adviser said “she and Ann bonded” when Romney backed Haley in 2010 and that’s why she stayed at the governor’s residence.

Susan Duprey, who is an adviser to Ann Romney and travels with her whenever she’s campaigning without her husband, said one of Ann Romney’s greatest assets is that “she shows a different side of Mitt than most people see on the campaign trail.”

“She’s able to show people what a devoted, caring and loyal person he is through the personal stories she tells of his support of her through their marriage. People really enjoy hearing about that side of him. She’s a representation of that side of him and I think that’s a huge positive that she has on display for him when she goes around the country for him,” Duprey said.

Duprey adds that when it comes to stumping for her husband while managing her MS, she’s “very disciplined about what she eats, getting enough rest along with her other medical help to keep the disease in remission.”

Duprey, who lives in New Hampshire with husband Steve Duprey - an old friend of John McCain who traveled with him across the country during his bid for the White House for 2008, said the Romneys are in love and “very connected.”

“She’s very smart and she’s also got a very good political antenna,”Duprey said. “A lott of  people that have those qualities have a harder edge and she does not carry that edge and that’s why she is so accessible to people.”

Despite her personal wealth, voters seem to relate to Romney’s story, especially when she shares her struggles with her MS – which is now in remission – or being diagnosed with early-stage breast cancer, undergoing a lumpectomy and radiation in 2008. They also eat up the Romneys love story, which was on full display at a gathering of conservative activists on Michigan’s Mackinac Island last month when they told their story of first falling in love at the vacation spot while still high schoolers.

Mitt Romney started dating Ann Davies when she was 15 and he was 17 and the son of then-Michigan Gov. George Romney. They stayed together when he went away to Stanford University for a year, and then to France to do his Mormon mission. She converted to Mormonism when she was 18 and they married two years later.

Anita Perry

Texas Gov. Rick Perry’s wife, Anita, is also a constant presence by her husband’s side since he got in the race in August.

She also has campaigned independently of her husband, opening campaign headquarters in Iowa and South Carolina, helping to fund raise for the campaign, and selling her husband’s credentials to voters. But it wasn’t until her frank comments about his lackluster debate performances that she started to attract attention from the media.

“He’s never had a debate class nor debate coach in his life,” Anita Perry told an audience in Urbandale, Iowa,  last month, according to the Des Moines Register. “He’s going to be better prepared this time.”

Perry campaign spokesman Mark Miner said Perry and his wife are “a team” and calls Anita “very down to earth and relates to people extremely well.”

“They’ve been through the rigors of campaigns numerous times in the past,” Miner said. “They’re a dynamic combination when you can have the governor in one place and her in the other.”

Anita Perry is a former nurse and daughter of a rural doctor and can use that experience in the health care sector to help her husband as his campaign battles against President Obama’s health care plan and in his effort to draw comparisons to Romney’s health care plan in Massachusetts.

The Perrys have something in common with the Romneys: long relationships.  After initially meeting at an elementary school piano recital, Rick Perry went on his first date with his wife in 1966 when he was 16 and Anita Thigpen was 14. They married 16 years later in 1982 and have two children, Griffin and Sydney.

Mary Kaye Huntsman

Former Utah Gov. Jon Huntsman’s wife, Mary Kaye, is also going to be a powerful tool in his all-out battle to win New Hampshire. The campaign announced last week that it is picking up and moving the entire campaign from Orlando to the Granite State, betting it all in the first in the nation primary.

Campaign spokesman Tim Miller says the former first lady of Utah “has been our top asset on the campaign trail,” and says Mary Kaye Huntsman has campaigned independently in both South Carolina and Florida as well as done local television interviews. Most importantly, she’s another person who can sing her husband’s praises and try to sell her husband to voters if he has to be out of the state. His daughters will also be on the trail in New Hampshire.

“Mrs. Huntsman will be on the trail often. Also, the advantage of Mrs. Huntsman campaigning as well as the daughters campaigning is when Gov. Huntsman is out fundraising or the very few days he will be out of New Hampshire between now and early January, it allows us to maintain a presence in the state,” Miller said.

Mary Kaye Huntsman’s biggest effort in Utah was her Power in You program, which helps at-risk youth. Suche issues are something she continues to highlight on the campaign trail and undoubtedly something she would work on as first lady. A campaign aide describes how Huntsman’s wife can more comfortably speak about the former ambassador to China than he can.

“Frankly, she speaks to Gov. Huntsman’s personal strengths a lot more naturally than he does in the sense of her willingness to talk about his character, how he is as a father, or to his strengths as his career moved from the business world to governor to ambassador. That is unique,” the aide said.

Marcus Bachmann

Although women dominate the would-be, first-spouse club, there is one man vying for the job: Marcus Bachmann.  Minnesota Rep. Michele Bachmann’s husband has been a near-constant presence on the campaign trail with his wife and has been referring to himself as the future “first gentleman” in fundraising emails.

“I promise you as first gentleman my role will be to honor America with dignity, class, and grace. I will never apologize for America, a country blessed and led by our Almighty God,” Bachmann said in the email. “Michele is a dedicated wife, mother, foster mother, friend, and respected leader of our country. I know as the next president, she will turn our economy around and put our nation back on a path towards prosperity.”

But for a while, it looked as though Bachmann was going to be a liability for his wife when a firestorm erupted after revelations that their therapy practice was advising clients that prayer could rid them of homosexual urges.

Callista Gingrich

Callista Gingrich has also been a constant presence not only on the trail, but on campaign literature and consistently promoting both her new children’s book and Gingrich Productions films. She’s active on Twitter, promoting her book tour and updates on their movies, but there aren’t as many tweets on the actual presidential campaign for former House Speaker Newt Gingrich. The last tweet that had a campaign focus was her promotion of their film, “Nine Days That Changed the World” being screened in the first caucus state of Iowa. That was Sept. 20. The former House speaker even introduced his wife at the Faith and Freedom coalition conference last month by touting her upcoming children’s book.

Karen Santorum

Rick Santorum’s family essentially moved to Iowa in August and his wife was at her husband’s Des Moines headquarters calling voters and stuffing envelopes. Along with her seven children, observers say, she is the added help the campaign needs in its all-out battle for Iowa.

Communications Director Hogan Gidley called Karen Santorum the ”campaign’s secret weapon” and said she will continue to be on the trail with her husband and out solo.

“Karen Santorum is not a high-priced consultant. She’s better.” Gidley said. “There’s no doubt Rick couldn’t and wouldn’t do this without her.

“She’s already given many speeches on behalf of her husband and she’ll give more in the future  because we know, when people meet and hear from Karen, they get to know Rick,” Gidley said.

Carol Paul

The Paul campaign says Carol Paul oversees the Paul household and things fall apart when she’s not home, but she will be out on the trail despite her low-key role so far. The Pauls’ son, Rep. Rand Paul, has been more visible out stumping for his father, but the campaign told ABC News that Carol Paul will be on the trail with her husband, Texas Rep. Ron Paul,  half the time.

Gloria Cain

Pizza mogul Herman Cain told The Daily Caller  that wife Gloria is “one of the most unassuming, not-looking-for-the-limelight-people you’ve ever met” adding not to “expect the traditional amount of exposure you normally get from a campaign wife.” Gloria Cain has been mostly absent from the trail, even as Cain’s campaign has enjoyed a boost since winning the Florida GOP P5 straw poll.

During the previous cycle, Janet Huckabee was next to her husband, Mike, on the campaign trail, stumping for him across the early states and especially Iowa, where he surprised the country with his come-from-behind victory. Her advice to this year’s crop of candidate spouses is “have fun” and that she and her husband, whom she has known since the seventh grade, would have snow fights to break up the “grueling” campaign trail.

“It is an incredible opportunity that few people get to experience, but if you don’t have fun and it’s like, ugh, I’ve got to get up and campaign, it’s going to be disastrous,” Huckabee told ABC News. “It’s very difficult …n o two days are the same. You’re in a different workplace every day because you’re in a different town or a different event. You have to be prepared for the unexpected.”

She added that she’s happy to be off the trail this time around, but said she “pushed him [her husband] to run more than anybody else.”

“People thought I held him back and I was saying do this. At the end of the day it was him deciding, but I really encouraged him strongly we need to do this, this time around,” Huckabee said.

Myra Gutin is a politics and communications professor at Rider University and an expert at the role of first ladies in history. She wrote a book about Barbara Bush as well as “The President’s Partner: The First Lady in the Twentieth Century.” She says campaign-trail spouses need to be both flexible and careful about what they say. Gaffes said after exhaustion on the trail can hurt a campaign.

“You have to be circumspect and be flexible. Both primary and general election campaigns are exhausting,” Gutin said.  “It’s much tougher than anyone thinks.”

Gutin advises spouses to be themselves, but stresses just how essential they are to any campaign, mentioning how it hurt Howard Dean’s campaign in 2004 when his wife, Judith Steinberg Dean – a busy physician – played a low-key role on the trail.

“I’ve always thought the first lady can play a very important role in a presidency,” Gutin said. “Ladybird Johnson used to say the first lady is the only person that can tell the president to shut up. She can give an honest opinion. She doesn’t represent any particular constituency. She can look at it and say this isn’t going to work.”

She added that first ladies are often the only people who can humanize their spouses. “A spouse can do a great deal of work,” adding that if there is a topic on which a spouse is focused, whether it be Anita Perry and health care or Mary Kaye Huntsman and at-risk youth, she (or he) should talk about it on the campaign trial because they are sure to focus on it once they get to the White House …  and it might help the spouse get there.

ABC News’ Michael Falcone, Arlette Saenz, Emily Friedman, Sarah Kunin, and Jason Volack contributed to this report.