Anita McBride, former chief of staff to first lady Laura Bush and a board member of the White House Historical Association, discusses the expectations that first ladies face, and the role Melania and Ivanka Trump could play at the White House. (Peter Stevenson/The Washington Post)

There's been plenty of chatter, though few hard details, about the roles that members of President-elect Donald Trump's family will play in the White House once he takes the oath of office on Jan. 20 — or even whether some immediate family members will make it to the White House at all.

His wife, Melania, and son Barron Trump will reportedly not move to the White House from Trump Tower in New York during the current school year — in fact, there's no hard date set for their arrival. And there's been discussion of the prospect of Trump's daughter Ivanka taking over office space usually reserved for the first lady.

But as the Post's Philip Bump noted, for all the chatter around that potential development, it would be a lot less unusual than people are making it out to be. For all tradition and ceremony generally surrounding any first family, there are of course no official constitutional duties for any of them but the commander in chief — and the role of presidential spouses and children has changed dramatically over time.

The Fix sat down with Anita McBride, former chief of staff to first lady Laura Bush and a board member of the White House Historical Association, to discuss the role of the first lady, how much power she really has, and how unusual it is — or isn't — for other members of the first family to take on big roles. Our conversation has been edited only for length.

THE FIX: The American people elect a president, and then their spouse comes into the White House and is not just given influence, but in more recent years, actually many first ladies have tackled very concrete policy issues. How does that set up expectations for the first lady, and what is she actually supposed to do during her spouse's term?

McBride: On Inauguration Day, at 12 o’clock, when the president of the United States takes the constitutional oath of office that gives him his responsibilities and his oath, the first lady of the United States assumes an automatic, powerful platform to which she has not been elected, and to which she gets to pick and choose what she wants to work on, because there is no statutory authority, or anything in the Constitution that gives her a role, gives the spouse a role. So with each occupant, it gets to be redefined. And I fully expect that that’s what we’ll see in this new administration

But we have come to expect certain work to be done by the first lady of the United States, and for them to engage in issues that really matter to people. They’re best at it when they choose things they really care about, and they can use that platform in ways that really provide them tremendous opportunities to make a difference.

Every problem in the world comes to the desk of the American president, and invariably the decisions that they make are going to be criticized, or are going to be critiqued; they’re not going to be popular with everybody. But a first lady gets to pick and choose what she wants to engage on, shine a light on something specific, be that public advocate, be that PR machine that is unmatched by any other surrogate for the president, and the United States. When you’re the spouse, you’re the closest person to the president. People listen to what you have to say, and invariably, they’re best at it when they pick something they care a lot about, they have credibility, they have authenticity, and it does lead to their popularity, because they can very much make a difference.

FIX: In our country’s history, the role of women in society has changed dramatically — when the constitution was written, we were more than 100 years away from women getting the right to vote. I’m sure that the role of the first lady was not what it is today, in, say, the 1800s. Are the expectations higher on first ladies now? Are they expected to show up on day one with policy goals?

McBride: It is true, there’s been an evolution of the role of women in our society, and by extension of course, there’s been an evolution of the role of the first lady. It’s been a bellwether of changes to come. Throughout our history, president’s spouses have played an important role for as leaders for women, in my estimation. And also the most important role they have is to be the support system for the president of the United States, who has all of the problems come to him.

In the 19th century, our first ladies were really consumed with a nation at war — a new republic fighting for its position on the world stage. Of course, in the 20th century, you had this enormous evolution of the women’s movement and the rise of social issues, in which first ladies have been engaged. The first first lady that had the right to vote, and she could cast a vote for her own husband, was Mrs. Harding in 1920. And then of course as time went on, we saw someone like Betty Ford, who championed the Equal Rights Amendment for women in the '70s, but it was a deeply unpopular issue for the president’s team in the West Wing, so she broke that mold a little bit by speaking out on an issue that she felt was important to women.

She also championed something that every woman in our country today, and women around the world, really have Betty Ford to thank for speaking out publicly against the stigma of breast cancer, and going public with having a mastectomy. She forever changed the way women’s health is viewed in our country, and particularly on the issue of breast cancer. We couldn’t have even mentioned the word “breast” in public in the mid-'70s, and she changed that.

FIX: There are some questions about the role that Melania Trump will play in her husband's administration. She did make a speech at one point about bullying, and how she feels like that’s something she really wants to speak out on. But there have also been indications that she may not play as large a role as, say, Michelle Obama has, and that Ivanka Trump may play a larger role. Is that unusual?

McBride: The American people have high expectations for how anybody that comes into these positions, how they use it, and really more so that they use it wisely, and do something that makes a difference. Like everything else in this campaign, this election, this transition, the playbook is being rewritten by Donald Trump and by the team around him. So I think at some point we have to accept the fact that this will be different — different from anything else we have experienced in White House history. But there are some historical precedents that the Trump administration can draw from, because there have been wives and sisters, daughters and nieces of presidents in our more distant past, that have fulfilled the role, if a president has been widowed, if he’d been unmarried.

For example, James Buchanan was a single man, and his niece Harriet Lane played a tremendous role, and was considered the first first lady of the White House.

And then we’ve had in modern times, daughters have had to step up to help. Particularly, I mentioned Mrs. Ford earlier, who’d had breast cancer and had a mastectomy, Susan Ford stepped in to support her father at social events, and others have done this. Chester Arthur’s wife was an opera singer, and she caught pneumonia at one of her performances, and died about 20 months before the inauguration, so Arthur’s daughter stepped up to fulfill the social hostessing roles that her mother had.

FIX: You mentioned that legal structure, and I think something a lot of Americans have concerns about is the president-elect’s business empire. Is it typical for first ladies or other family members becoming involved with the administration to divest themselves from those interests?

McBride: For the American people to have faith in their institutions of government, that we trust them to operate aboveboard and fairly, then there are those firewalls that they need to know are in place, and that they’re confident that the legal decision-making behind these ways that you can operate are firmly in place. We haven’t had a president before like this, who has such a massive business empire around the world, and by extension members of his family that are their own CEOs and own entrepreneurs. I suspect that as they’re reviewing all of the ways that they can make this happen properly, that that’s why it’s taking a little bit longer, and the decision has been delayed. I actually take great comfort from that, that this is not going to be a knee-jerk decision, but it’s going to be one that’s very thoughtful, appropriate, legal and ethical. Because there is one thing that I can definitely tell you: No first family member, whether it’s a spouse or a child, wants to be a distraction to the president of the United States. That just doesn’t help anybody.