– A few months ago, when Rachel Roberts, a 44-year-old owner of yoga studios in Newport, Ky., decided to run for state Senate as a Democrat, her newly hired campaign manager sent her a packet of photographs of successful women and suggested she pick one and model her campaign look accordingly.

“There was Nancy Pelosi and Sheryl Sandberg,” Roberts remembered, rolling her eyes. The problem: “That’s not who I am. I spent the last seven years in Lululemon.”

At a time of smartphones and instant imagery, when unprecedented numbers of women are running for office and often placing their gender at the center of campaigns, it is impossible to ignore the role that image can play in positioning. After all, if you are going to be the change, don’t you have to look the change?

Eighty women, including Roberts, recently came to Yale University to attend the 2018 Women’s Campaign School (WCS) and, among other things, try to answer that question. An intensive five-day course, hosted although not administered by the Yale Law School, it helps prepare women to run for office, get ready to help others run for office and establish political networks. The course includes seminars in how to do a stump speech, budget for media and direct mail, raising funds, determining voter turnout — and deciding how to deal with the pantsuit. Or, as one two-hour session was titled, “Dress to Win.”

But what, exactly, does that mean?

It’s a complicated question in a world where for a long time the best approach was wearing a man’s suit in a different color, a world where women have long chafed against being judged on appearance. Indeed, many women resent that the question is asked at all.

“The reaction is always mixed,” said Karen Petel, referring to the style session. Petel is the founder of a namesake political consultancy, former political director of the Democratic Congressional Campaign Committee and a board member of the campaign school.

“There’s no doubt that how you present yourself matters, but we have so little time and there is so much to cover,” said Shannon Lynch, a 26-year-old producer of a political talk show on Sirius XM in Washington, D.C., who was at the campaign school to test her own appetite for office. “Do we really have to spend two hours on this?”

Patricia Russo, executive director of the Women’s Campaign School, said the answer is increasingly yes. “It’s not fair, but this is the reality,” she said.

As Michelle Dhansinghani, 28, the founder of Elan Strategies, who plans to run for Congress in 2020 from her home state of Texas, said: “What you project is what people believe. And the standards are higher when you are a woman, and even higher if, like me, you are a woman of color, and even higher if, like me, you are a woman of color from one of the poorest parts of your state. Texas has never had a Latina congresswoman.” (This year, two Latina women are running.)

Although the WCS, which is nonpartisan, was founded in 1994 because “there are simply specific gender challenges to running for office,” the “Dress to Win” session did not exist until five years ago. That is when, Russo said, “it became clear this is part of the package, and students were confused about it.”

Now the campaign school is trying to teach those students to see dress not as a liability to overcome but as a weapon that women are lucky enough to wield.

“People are judging you,” said Sonya Gavankar, the lecturer in charge of “Dress to Win,” at the opening of her class. A onetime Miss America contestant, she is director of public relations for the Newseum in Washington and has a sideline as an image consultant. Even if you are being judged, she argues, it does not mean that you should fall back on the safety net of banal dressing.

“When you put on the black suit and the patriotic scarf, that does not tell people to pay attention,” she said. “It tells people: ‘I am boring. And maybe an FBI agent.’ It presents the most bland version of yourself. It’s not going to inspire people to want to hear what you say. Let the men be boring. You can be different.”

This is easier said than done, however. At issue is the tension between two schools of thought. On the one hand, there is the traditional wisdom regarding female candidates and how they dress. “Your clothes should not speak for you,” said Rosana Vollmerhausen, the founder of DC Style Factory, a wardrobe consultancy that works with female and male political candidates. And on the other, there is the growing belief, apparent at WCS Yale, that clothes should absolutely say something about who you are and what makes you different.

“We are living in a reality TV world,” Joel Silberman, a media trainer who runs a class titled “Magnifying your Magnificence,” told the class. “Everything about your presence has to be on purpose, and I need to see it in five seconds.” “See” being the operative word.

The problem is that there are few examples of what that might actually look like — and few of them take budget into account, a very real concern for many of the women at WCS Yale. When pressed, Petel cited Michelle Obama, who effectively expanded the definition of what a first lady might wear, eschewing suits for printed, often sleeveless, dresses, mixing J. Crew with Jason Wu and generally appearing to have fun with her clothes. But she was not actually the candidate.

Stacey Abrams, the Democratic candidate for governor in Georgia, whom Petel lauded for championing the dress, may be a better example. Ditto Rosa DeLauro, a U.S. representative from Connecticut, who once earned the sobriquet the “hipster congresswoman” because of her quirky choices, often involving ruffles, stripes and sofa prints.

Then there is Cynthia Nixon, who is running for New York governor and who wears the formerly requisite pantsuit with a modern edge. (White winklepickers, anyone?) And further afield, there is Theresa May, the British prime minister, who was famous for her show collection, which included leopard court shoes and over-the-knee stretch leather boots.

But there is no question that the dominant dress code and mind-set still hews to the Elizabeth Warren/Hillary Clinton/Kirsten Gillibrand mold. (Gillibrand is perhaps the most well-known graduate of the WCS, along with Gabrielle Giffords, although both attended before the clothes issue became part of the curriculum.)

That mold says the pantsuit — and its cousin, the stewardess skirt suit — is the Garment Least Likely to Offend Any Interest Group, and thus the garment of choice. All else is a risk.

In the end, Gavankar said, female candidates “are not playing it safe with their views. So why should they play it safe with their clothes? When we tell women to wear the same suit, that is doing a disservice to women. They are, and should be, different.”

With one caveat that everyone can agree on: Once a candidate finds a style that feels natural, whatever that may be, she needs to stick with it. Flip-flopping in the middle of a campaign, whether it be clothes or platforms, is not a good idea.