Once again the white suit rears its powerfully symbolic head. There are few garments in the political wardrobe that have been worn so deliberately and become as imbued with meaning. This time it has stepped front and center thanks to the saga of State Representative Justin Jones of Tennessee, a Democrat and, at 27, one of the youngest Black lawmakers in the state government.

Mr. Jones and his fellow representative Justin J. Pearson came to national attention on April 6 when they were expelled from the legislature over a protest for gun control. Mr. Jones was reinstated on Monday by the Nashville Metropolitan Council, his district’s governing body, but by then his image had already gone international: a totem of what it meant to stand up to, as he called it in a fiery speech from the House floor on the day of his expulsion, the “flexing of false power.”

See, on the day of his expulsion, Mr. Jones was wearing what The Tennessean called his “trademark white suit” with a white shirt and light brown tie, his hair pulled back in a ponytail. The image of him walking out of the woody chamber with a fist held high, glowing from every angle, made for an indelible picture.

“The world is watching,” he said, and it was. Since then, photographs of him in the suit have not just appeared again and again online and in news reports (even in stories about his return, rather than the sage green he wore at the time), but have also been used as a clarion call in emails by political action committees.

As Alison Cook, of The Houston Chronicle, tweeted, it was simply a “masterstroke of presentation.” One made by a member of a new generation that understands just how useful a picture can be to make a point in a social media age.

When it comes to protest, after all, the white suit contains multitudes. It has become a dress code of a different kind.

In 1917, white was the color of the Silent Protest Parade, organized by the N.A.A.C.P., in which some 10,000 Black Americans marched down Fifth Avenue in protest against discrimination and anti-Black violence. In 2020, white was the color worn by the 15,000 attendees of the Brooklyn Liberation March, a protest for Black trans rights in front of the Brooklyn Museum that was directly inspired by the Silent Protest.

In 2016, the white suit became a viral contemporary metaphor when Hillary Clinton donned a Ralph Lauren version to accept her nomination as the first female presidential candidate of a major political party, choosing to connect her history-making appearance to that of Geraldine Ferraro, who wore white when she became the Democratic Party’s first female nominee for vice president in 1984. And, before that, its genealogy can be located in the suffragist tradition and the National Woman’s Party, whose members wore white, “the emblem of purity,” because it “symbolizes the quality of our purpose.”

(“Quality of purpose” being as good an explanation as any for what most protesters are trying to convey. Including, presumably, Mr. Jones, though emails to his office about his image-making were not returned.)

Since then, the white pantsuit has served in the United States as sign of female power and solidarity. It was worn by the women of the House at the State of the Union in 2019 in acknowledgment of their growing numbers and by Nancy Pelosi later that year when, as speaker of the House, she announced the decision to begin drafting articles of impeachment against President Donald J. Trump.

And not just in America. In 2003, “the Ladies in White” movement was founded in Cuba, a group of female relatives of jailed dissidents protesting the government’s abuse of power; in 2017, the Iranian activist Masih Alinejad introduced #WhiteWednesdays as part of her movement, My Stealthy Freedom, to oppose compulsory veiling of women and girls; and in 2019, an image of a woman standing on a car in a white thoub during the Sudanese protests against President Omar al-Bashir went viral.

All of these potential associations are contained within the seams of Mr. Jones’s white suit, said Richard T. Ford, the author of “Dress Codes: How the Laws of Fashion Changed History” and a professor at Stanford Law School. Not to mention the tradition of “Sunday best” in the Black church, as well as that of the plantation owners in their white mansions.

“In one sense, it’s mixed metaphors,” Mr. Ford said. “But it works. We instinctively read his white suit as both a symbol of political dissent and a statement of continuity with tradition. It says, ‘I dissent, but I also belong here in the corridors of power.’”

At it happens, Mr. Jones had also worn the white suit on Feb. 6 for the governor’s State of the State address, another highly public occasion, suggesting that the lawmaker understood exactly how much of a visual statement a suit could make at select moments, even when he wasn’t speaking at all. He is appropriating and redefining its narratives.

Cheri Bustos, a former congresswoman from Illinois, said that for her it was a reflection, like Mr. Jones’s willingness to rally for his beliefs, of the way the younger generation of elected officials are “challenging norms.”

“It feels disruptive because it is,” she said.

And, she added, “it can also lead to meaningful change.” First “in outward appearance” and then, perhaps more important, “in political norms.”