Sarah Remes carries cards and letters to the Russell Senate Office Building on behalf of out-of-town friends. (Matt McClain/The Washington Post)

They climbed the marble staircase, then trudged back down, realizing they were on the wrong floor. They retraced their steps through a long hallway after wandering past the office they were looking for. They were new at this, but they were on a mission — on behalf of far-flung allies who couldn’t carry it out themselves.

“Good morning!” Sarah Remes said as she stepped into the office of Sen. Lindsey O. Graham (R-S.C.), her puffy parka draped over her arm and her 7-year-old son, Isaac, trailing behind her.

“We’re here from D.C., and we don’t have our own senators,” Remes pointedly told a smiling receptionist. “But we have some friends who have written some nice cards and letters . . .” She turned to Isaac, who presented a sheaf adorned with rainbow flags and smiling faces of all colors, handmade by friends in South Carolina.

“The gist of them is that we are all so happy to see Senator Graham’s comments on refugees,” Remes added, “and we’d love to see some votes to back that up.”

In the months since Donald Trump’s election, a grass-roots liberal opposition has rapidly mobilized, circulating action items and to-do lists across social media. But most have focused on the importance of calling one’s elected reps — a tactic that has left aspiring activists in the vote-deprived but heavily Democratic nation’s capital feeling a little useless.

So a growing number of them have figured out a way to compensate: by serving as a proxy and a personal letter carrier for out-of-state pals.

Remes first encountered the concept through a blog post on Facebook, but there’s also “BeLoud D.C.,” a new group of local activists who surveyed voters in Iowa and Pennsylvania on a range of political issues and carted their responses in hefty bound volumes to the offices of Republican Sens. Charles E. Grassley and Patrick J. Toomey, respectively. Susie Hayward, a Minnesota native who offered to represent friends and relatives in her home state, even sweetened the transaction by baking cookies to accompany a stack of thank-you notes for Sen. Al Franken (D).

It was the first time any of them had served as a stand-in on Capitol Hill. All of them said they planned to do it again.

“It felt like the building was kind of empty, and it made me think that we could do a lot more to be there and to make sure that these concerns are heard more regularly,” said Jordan Lloyd Bookey, a founder of BeLoud D.C.

Hayward agreed: “Lots of my friends in other states are frustrated because they’re not getting through to their reps — all the voice-message boxes are getting filled up,” she said. “Now I can show up and deliver that message.”

Remes and her son Isaac talk to Kathleen Hunt, a staffer in the office of Sen. Tammy Duckworth (D-Ill.). (Matt McClain/The Washington Post)

Remes, a former immigration attorney who lives with her husband and their two kids in Northwest Washington, said she has always been invested in politics, but not to this degree. For a while, she spent mornings on the phone after the kids left for school, dialing up members of Congress and citing the Zip codes of out-of-state friends (“I know they wouldn’t mind”) to deliver her talking points — urging them to vote against Trump’s education secretary nominee, Betsy DeVos; thanking Sen. John McCain (R-Ariz.) for speaking out on behalf of immigrants; and bugging Rep. Jason Chaffetz (R-Utah) to investigate Trump’s ties to Russia.

“But until I saw that Facebook post, I wouldn’t have thought about going downtown, to take advantage of being able to be there in person,” she said.

So, on a blustery February morning, Isaac skipped school, and they took the Metro from Friendship Heights to Union Station.

“The security is like the airport,” Isaac noted, impressed, after they passed through a metal detector into the Hart Senate Office Building. Inside the grand entrance, Remes pulled out a handwritten letter on a torn-out sheet of college-ruled paper, written for Sen. Kamala D. Harris (D-Calif.) by Isaac’s grandmother, who lives in Palo Alto.

“Dear Senator Harris,” Remes read aloud, bending down beside her son. “Thank you for being caring and supportive of your voters. Please continue to stand up for our rights by filibustering the nomination of Neil Gorsuch for the Supreme Court and voting ‘no’ on Mnuchin, Pruitt and Puzder.” (This was before Andrew Puzder dropped out of consideration for the post as labor secretary.)

Isaac nodded solemnly.

Remes consults her phone and her sheaf of letters. “We have to keep up this energy,” she said. (Matt McClain/The Washington Post)

At Harris’s office, a young staffer took the letter and listened politely as Remes explained that her mother-in-law wanted to see continued opposition to Trump’s nominees. Then the pair rode the elevator to the fifth-floor office of Sen. Tammy Duckworth (D-Ill.), where Remes repeated her practiced refrain: “Hi,” she said. “We’re from D.C., and we don’t have any senators.”

“Great!” the woman at the front desk said.

“Well — not great,” Remes said.

“Well, great that you came in,” the woman clarified.

Climbing to the seventh floor, Isaac peered over the marble balustrade: “Now we’re really high up.” A staffer for Sen. Richard J. Durbin’s (D-Ill.) was careful to collect an address for Remes’s friend in Evanston, Ill.: “I’ll make sure that she gets a response,” he assured.

And then they were done. Each office visit had lasted all of five minutes. Activism, it turns out, can be simultaneously satisfying and vaguely anticlimactic. But heartfelt messages had been delivered to four Senate offices. Remes had taught her son something about participating in democracy. Isaac had scored a Milky Way from the candy basket in Durbin’s office.

At first, Remes imagined that she might make this sort of trip once a week. Now, as the two made their way out, she was deciding to pace herself: “This is a marathon,” she said. “We have to keep up this energy.”

But, she added: “We’ll be back.”