Ralph Lauren has dressed his fifth first lady.

On Friday, Melania Trump wore a powder-blue cashmere dress and matching bolero jacket by the designer as her husband, Donald J. Trump, was sworn in as the 45th president of the United States. Though Mr. Lauren’s designs have been worn by first ladies from Betty Ford to Nancy Reagan and Michelle Obama, the reference this time was clear: Jacqueline Kennedy. From bouffant to mock turtleneck collar to light pastel shade.

Mrs. Trump has said that she looks to Mrs. Kennedy as a role model, and at least as far as her image goes, it seems she is taking that literally.

The Ralph Lauren look was the third outfit by a New York designer that Mrs. Trump had worn since the inaugural festivities began, which connects Mrs. Trump not only to the American fashion establishment, but also to American history.

It was, in other words, a very considered choice. Especially because Mr. Lauren is a designer who has built his empire on selling the myth of the American dream. And especially because Mr. Lauren was most recently, and closely, associated with Hillary Clinton.

(Indeed, Mrs. Clinton also wore a Ralph Lauren suit to the swearing-in: a white trouser style very reminiscent of the Ralph Lauren suit she wore to accept the Democratic nomination for president — then and now a pointed nod to the color of the suffragists and the women’s movement. As it happens, and probably not coincidentally, Ivanka Trump also wore a white pantsuit to the swearing-in, though from Oscar de la Renta.)

If you wanted to send a message about putting the past behind you, learning from peers, and embracing both the establishment and the office, you couldn’t do much better than that.

Along with Mrs. Trump’s appearance on Thursday in a dress and military-inspired cashmere coat by indie brand Norisol Ferrari to the wreath-laying ceremony at Arlington National Ceremony, followed by a beige sequined gown by the Lebanese-born Reem Acra to the black tie donor dinner at Union Station, the choice of Mr. Lauren suggests that the new first lady and her team may indeed be thinking about how to use clothes to communicate.

A spokesman for Mr. Lauren explained the decision as being guided by his respect for the office. In a statement, he said: “The presidential inauguration is a time for the United States to look our best to the world. It was important to us to uphold and celebrate the tradition of creating iconic American style for this moment.”

Now the question is whether this theme continues at the inaugural balls on Friday night, or whether Mrs. Trump will wear a gown by, as has been rumored, Karl Lagerfeld. He is the creative director of both Fendi and Chanel, but his namesake line is licensed to G-III, an American group that also owns the license for the Ivanka Trump brand. We’ll find out soon enough.