Jennifer Siebel Newsom has made an unprecedented move in American politics by shunning the traditional title of "first lady" of California and instead choosing to be called "first partner."

"Being First Partner is about inclusion, breaking down stereotypes, and valuing the partnerships that allow any of us to succeed," Siebel Newsom wrote on Twitter on Jan. 11, a few days after her husband, Gavin Newsom, was sworn in as the state's new Democratic governor. "Grateful for this opportunity to continue advocating for a more equitable future."

While Siebel Newsom was unavailable for comment, her communications director, Hannah Milgrom, told CBC the "first partner" decision was a natural step given Siebel Newsom's activism on gender issues. "She wanted to break down the stereotypes that we associate with being a politician's wife," Milgrom said.

The term "first lady" feeds into the traditional notion that the elected official is a man and his spouse is a woman, said Milgrom. Changing the title to first partner could help open up people's minds to other possibilities, she said.

Being First Partner is about inclusion, breaking down stereotypes, and valuing the partnerships that allow any of us to succeed. <br><br>Grateful for this opportunity to continue advocating for a more equitable future - now let’s get to work! <a href="https://t.co/sXwfev7BFy">https://t.co/sXwfev7BFy</a> —@JenSiebelNewsom

Alex Rooker, acting chair of the California Democratic Party, thinks there is a good chance "first partner" could catch on among other political spouses, male or female, throughout the U.S.

Praise and criticism for new title

She said Siebel Newsom's choice represents "a very fresh approach" and that it has been "received extremely well here in California."

"People like her vision of being a strong, independent person," said Rooker.

The decision inspires "me, a lot of individuals, and communities, to change the limiting gender stereotypes and start shifting norms," Rooker added.

The norm has been an expectation that first ladies, whether in the White House or governors' mansions, should attend galas and events, engage in charity work and take up causes to champion. Wives of past presidents and governors have met those expectations to varying degrees. Rooker said Siebel Newsom intends to work on policy issues, such as health care, right alongside her husband.

Some critics responded to Siebel Newsom's tweet by saying her new title is "stupid," "not necessary," "way over the top" and "PC nonsense."

Jennifer Siebel Newsom directed the 2011 documentary Miss Representation, about women in media. (The Associated Press)

Melissa Haussman, a professor at Carleton University who specializes in U.S. politics, and in gender studies, wonders whether there is an ulterior motive at play. Perhaps Siebel Newsom's decision could benefit her husband's political image, she noted.

"Call me a cynic if you will, [but] I think it's probably more about positioning him as the uber-progressive," said Haussman. "I think this is all part and parcel of a certain image that Governor Newsom is trying to put forward."

Supporters say it was Siebel Newsom's personal decision to go by first partner, and that her husband was supportive of it.

Siebel Newsom has most recently been working as a filmmaker, and in 2011, she wrote and directed Miss Representation, a documentary on women in the media, which led to the creation of a non-profit organization called The Representation Project.

In 2015, she made a second film, The Mask You Live In, about society's definition of masculinity. She's currently working on a third film on this theme, The Great American Lie, according to her bio on the governor's website.

Will other political spouses follow suit?

Katherine Sibley, a history professor at Philadelphia's St. Joseph's University who specializes in the history of first ladies, said that California is known as a trend-setting state. It's the most populous and has a huge economy, and because of California's influence nationally, Siebel Newsom has a more visible platform than if she were from a smaller state, said Sibley.

She said Siebel Newsom also has Hollywood connections, thanks to her career in filmmaking and her past work as an actor, which could help elevate her messages on gender equality.

Sibley said all this comes at a time when people are starting to look at the role of a first lady differently — and when the term "lady" itself is becoming increasingly "antiquated."

"We are living in a moment where there's a lot of open doors for different kinds of names and practices in some of these more traditional positions," Sibley said.

When Hillary Clinton was running for president in 2016, some asked what her husband, Bill, would be called if she won. He never indicated whether he would take on the title of "first gentleman" or something else. (Complicating the matter is the fact that in the U.S., former presidents retain that title after leaving office, which is why, to this day, Bill Clinton is still referred to as "president.")

First gentleman is the title used by the husbands of some women governors currently in office, such as in Oregon, Rhode Island and Iowa.

When Hillary Clinton ran for the U.S. presidency in 2016, people asked what the former president, Bill Clinton, would be called if she won. (Patrick Semansky/Associated Press)

Canada doesn't use titles like "first lady" or "first gentleman." Prime Minister Justin Trudeau's spouse, Sophie Grégoire-Trudeau, is referred to simply as the spouse, or wife, of the prime minister. The PM's spouse is not expected to take up particular causes and charity work, as is the tradition for the first spouse south of the border.

Haussman, the Carleton professor, described Siebel Newsom's move as interesting and path-breaking, but also questioned its true impact.

"What's it going to mean for U.S. politics? I'm not sure it will bring about a whole lot of change," said Haussman. "This is a great turning point, but this is one state out of 50."