It’s the latest sign of the times in an evolving Congress: stacks of black garment bags, stuffed with blazers, gowns and dresses, deposited in piles at UPS drop-off spots on Capitol Hill.

They contain the latest fashion choices for the women of Congress — members and staffers alike — who are increasingly turning to a popular online retailer to look on trend and polished while doing their demanding jobs. They are borrowing outfits — individually, or on an unlimited basis — from Rent the Runway, which allows women to efficiently rotate their wardrobes without breaking their budgets (while providing free shipping, dry cleaning and that clutch backup size). It’s an easy way for them to ensure they don’t make the faux pas of wearing the same outfit twice.

The wardrobe assistant has become a power tool for powerful women as RTR has expanded its offerings from black tie to casual apparel and work wear, making it a staple for the increasing number of women occupying high-profile and elected positions in Washington.

“It was amazing to walk by the mailroom on Capitol Hill packed with RTR garment bags,” Rent the Runway CEO and co-founder Jennifer Hyman said in an interview of her visit with young lawmakers to discuss her business this past fall. “Through RTR, we’re giving women on the Hill back the time and energy they’d typically spend on shopping so they can focus on their most important investment, themselves.”

The Washington Post spoke with a half dozen congressional women who use RTR, which offers several ways to “access your dream closet.” They include renting individual pieces for four to eight days at variable prices; an $89 monthly plan providing four pieces monthly; and a popular $159 monthly “unlimited” service allowing users to “access a constantly rotating wardrobe” and swap an item for something else anytime.

The in-vogue options seem to be enhancing Capitol Hill style, long considered an oxymoron. Drab power suits, usually a staple in Washington, can now be more easily replaced with bold blazers, floral blouses and sleek dresses. Once strictly a destination for that sparkly green sequin dress offered on the site’s homepage on a recent afternoon, the site has expanded to a selection of outfits appropriate for news conferences, office parties, cable TV appearances and even the campaign trail, among the regular offerings. Accessories are available, too.

“Fingers crossed that Nancy Pelosi joins soon!” Hyman added.

Hyman didn’t provide exact figures for the number of RTR customers on the Hill, but her spokeswoman, Sarah Edelstein, said the company has seen “tremendous growth in our D.C. market in the last year,” which has been fueled by new kiosks around the city where rentals can be returned and new items ordered.

But the number of female congresswomen is climbing — a record 104 women serve in the House — and so has the scrutiny of them, including of their appearances.

“It would be hard to say this tactfully,” said a House Democratic aide and an RTR unlimited subscriber who like others spoke on the condition of anonymity because they didn’t feel it was appropriate to speak on the record about their wardrobe, “but women who are lawmakers are photographed and scrutinized on their appearance — and this is one of the tools to feel more empowered in the workplace.”

Reps. Alexandria Ocasio-Cortez (D-N.Y.) and Stephanie Murphy (D-Fla.) are just two of the busy lawmakers who have publicly acknowledged they use RTR, in part to avoid repeating outfits during high-profile appearances.

Murphy, who is the chair of the House’s Future Forum — a generational caucus that includes nearly 50 of the youngest members of Congress — invited Hyman to appear before the group as a featured guest in September. Somewhat of an evangelist for RTR’s unlimited program, she praised Hyman for her paid family leave policy and structuring her company “in a way that is consistent with American values.”

The Florida lawmaker also made note of Hyman’s status as one of the few female co-founders of a company that has achieved “unicorn status” after a new round of financing that bumped up its valuation to $1 billion.

“I personally use Rent the Runway because it provides some diversity to my wardrobe, especially in a city that I find a little boring as it relates to fashion and need to express myself through fashion,” Murphy said of the service. “But more than that, I am a big fan of Rent the Runway for the type of company that they are. They embody what I call corporate patriotism.”

Ocasio-Cortez’s office declined to comment for this story.

An unlimited RTR subscription saves time and curbs the weekly dry-cleaning bill. But the monthly fee is a substantial investment for those on the salary of a public servant.

However, some women like Murphy, conscious of voting with your wallet, have rationalized the expense for reasons that go beyond the superficial: as a way to support a business that touts progressive workplace policies and saves more than 5 million pounds of total waste through recycling garment bags, plastic and hangers, according to the company.

“The truth is, the fashion industry is the second most pollutive industry on Earth, and no brand has addressed this broken system of consumption the way RTR has,” Hyman said.

Of course, some staffers use the service simply because they want to look stylish on a budget.

“I do it purely for selfish reasons and budget reasons,” said another staffer on the Hill. “I think that pressure to dress the part on the Hill is actually overstated — you can totally find things on discount at Old Navy that look great … a lot of people here don’t make a lot of money.”

“I personally like mixing in more expensive pieces with cheaper clothing,” she added.

The increasing use of the rental service has also sparked some fashion envy when a coveted item is spotted on the Hill and can be searched for online.

“You know AOC’s lavender pantsuit? I think it’s Theory,” remarked the House Democratic aide who described trawling the website to “favorite” outfits one day over a congressional recess earlier this year.

According to an internal study conducted by RTR in 2018, the average American woman only wears 20 percent of her wardrobe — and 50 percent of the pieces in her closet are worn three times or less.

“It’s boring and expensive to buy new work clothes and not a fun part of your day to look at your closet and think about what boring dress you’re going to wear again,” said a Senate aide who is preparing to temporarily suspend her unlimited subscription to RTR in the new year — once the holiday party circuit has been exhausted.

There are times when the unspoken code of a shared wardrobe inevitably becomes a topic of conversation, like when two women who work for the same lawmaker showed up to the office in the same dress one day, a male Hill staffer who witnessed the coincidence recounted to The Washington Post.

“So that’s what those black bags are all about,” the staffer remarked.