At Tuesday night’s State of the Union, for the third year in a row, Democratic women in Congress will dress alike to make a political statement. This year, they’ll wear white for the suffragists. Last year, it was black with red buttons for victims of sexual assault and harassment. At President Trump’s first address to a joint session of Congress, in February 2017, they also wore white — ostensibly as a nod to the suffragists, but also, not so subtly, to Hillary Clinton.

It’s the one night of the year when the nation’s eye is trained on the 535 members of Congress, all at once. Democratic women have harnessed that moment to create a powerful visual, broadcasting their shared gender identity.

Republican women, by and large, have not.

While the Democratic Women’s Working Group invited both Democratic and Republican women to wear white to the State of the Union in an announcement last Tuesday, female leaders within the GOP have yet to issue a similar call to members of their own party. (It’s unlikely that Republican women will wear white, since the color, linked to the #WearWhiteToVote hashtag circulated by Clinton supporters, has come to symbolize anti-Trump sentiment.)

GOP women have made a few attempts at wardrobe coordination in the past. In 2017, a handful of Republican women wore purple to show support for bipartisanship. Last year, a larger contingent wore either red, white, or blue to honor the troops. But while dressing in a single color suggests a clear message — we are women and we (at least in some things) stand as one — three different colors didn’t quite make the same point.

And maybe that was intentional.

“Historically, the Republican Party has not embraced identity politics, particularly along gender lines,” said Betsy Fischer Martin, the executive director of the Women and Politics Institute at American University. Republican women, she told me, are much less likely than Democratic women to “wear their gender as an asset.” Throughout the 2018 campaign season, she saw democratic women invoking their gender — running campaign ads featuring shots of them breast-feeding, reading sexist comments directly into the camera — far more often than their Republican counterparts.

Female candidates were making those decisions for a reason. According to a study conducted by the Women and Politics Institute in the run-up to the 2018 election, 69 percent of Democratic voters thought there were too few women serving in Congress, while just 33 percent of Republican voters felt the same way.

“Republican men and women both think it’s important to have more Republican women elected, but they think it’s important just to have more Republicans elected,” Kristin Soltis Anderson, a Republican pollster and author of “The Selfie Vote,” said at a recent event on GOP women in congress held in Washington, D.C.

Republican women are less inclined to accentuate their “womanness” on national TV because gender “isn’t the foot they want to be leading with,” said Olivia Perez-Cubas, communications director at Winning for Women, a political action committee dedicated to electing more Republican women to Congress. A congressmember’s gender, she says, isn’t as “relevant” within the Republican Party as it is on the other side of the aisle.

The dwindling numbers of GOP women in Congress — 21 in the House and Senate, compared to 106 on the Democratic side — may also help explain GOP resistance to dressing in uniform, said Perez-Cubas. “It just wouldn’t be as striking of an image.” A TV shot of Republican congresswomen, all wearing one color, next to Democratic congresswomen, wearing another, would highlight the significant difference in the number of women serving in both parties.