For 10 straight days and nights this month, Rosario Reyes did not eat. Each morning, she camped next to a monument in Lafayette Square, across from the White House. Each evening, she returned to a bunk bed at a nearby church. During the fast, she turned 36, received communion, watched tourists eat lunch, and tried to balance her water intake with her need to find a bathroom every few hours.

Reyes is a part-time babysitter and mother of three who has lived in suburban Maryland for a decade. She is also an illegal immigrant from El Salvador, and she had vowed to remain in the park without eating until President Obama signed an order offering temporary legal status to immigrants in her situation.

“My back is getting sore. My mouth tastes bitter,” Reyes said Sunday, huddled near the monument with five other women who volunteered to fast in response to a call from an advocacy group called Dreamers’ Moms USA. They knew a cold spell was coming soon but had arranged to bring extra clothes and blankets.

Since Congress failed to pass immigration reform last year, the president has promised repeatedly to take executive action to defer deportation for some of the estimated 11 million adults who are in the country illegally, just as he did for half a million such youths in 2012.

Now, with Republicans poised to take control of both houses of Congress, Obama has again pledged to take action, triggering threats of retaliation by Republicans but raising hopes among illegal immigrants, including thousands in the Washington area, who see the president as their last chance for relief.

Rosario Reyes, from El Salvador, is comforted by her son, Victor Reyes, 6, before Rosario leaves her home in Gaithersburg to resume her protest in Lafayette Square in Washington. (Sammy Dallal/For the Washington Post)

White House aides have said the order, which may come next week, would give priority to parents of U.S. citizens and “dreamer” youth, benefiting up to 5 million people. Reyes would be an immediate candidate for such protection because her youngest son Victor, 6, is a U.S. citizen, born in Maryland, and her oldest son, Ricardo, 19, obtained temporary legalization as a dreamer last year. Her husband, Ramon, 40, a janitor, has semi-permanent legal status as a refu­gee.

If the president does not act, Reyes will remain in limbo, subject to deportation and unable to legally work, drive or travel to El Salvador to visit her middle son. Jose Ramon, 13, lives with his grandmother and is reaching the age when criminal gangs will target him for forced recruitment.

“I worry about him all the time. When I get hungry out here, I think about him some more,” Reyes said in Spanish.

The Reyes family is typical of hundreds of thousands in this country from Mexico and Central America whose members include illegal immigrants, U.S. citizens and others who live overseas. Advocates said that legalizing parents of legal children is a logical first step toward solving the broader immigration problems Congress has failed to tackle.

“If the president liberates 5 million immigrants to work and live here legally, it will be an extraordinary step in the right direction, but it is not enough,” said Gustavo Torres, executive director of Casa de Maryland, a nonprofit immigrant advocacy group. “We still need to go to Congress and tell them it is time to resolve this crisis for all of our families and communities.”

To many Americans, though, Reyes’s status as a mother of two legalized children should not absolve her from having entered the country illegally. Some adamantly oppose granting “amnesty” to such lawbreakers and label U.S.-born children, such as Victor, “anchor babies” because they give undocumented parents a legal perch and extra incentive to stay. The surge of more than 50,000 minors arriving at the U.S.-Mexico border in recent months added to public concern about illegal immigration.

“If the president enacts amnesty for up to four and a half million people with children who are citizens or permanent residents, it will not be immigration reform but the dismemberment of our immigration laws,” said Jessica Vaughan, a researcher with the nonprofit Center for Immigration Studies in the District. “It would be a huge burden on taxpayers and create job competition for Americans and legal immigrants.”

Rep. Raul Grijalva (D-Ariz.) came out to talk with “Dreamer Moms” as they rallied outside of the White House on Thursday ahead of President Obama's address on immigration. (Arelis Hernandez and Ashleigh Joplin/The Washington Post)

Instead of curbing illegal immigration, such a mass forgiveness could make it worse, Vaughan said. Referring to the border surge, she said, “if there is anything we have learned from recent experience, it is that even talk of amnesty inspires people to send for their family and friends because they get the message they’ll be allowed to stay.”

Reyes, fasting alongside five other Latina mothers from around the country, said she viewed the issue as one of family survival and her act as a form of personal, silent protest.

Sitting for hours under a blanket, she tried not to think about food and looked forward to periodic distractions — the church volunteers who brought guitars, the doctor who came to check vital signs, even the U.S. Park Police who kept poking around, making sure the women did not spread out sleeping bags and kept their mini-camp free of clutter.

At least once a day, Spanish-language TV crews show up to film. Often, tourists or passersby stop to ask about the protest, and a few have signed a poster with messages saying “Good luck” or “God bless you.” But most keep walking.

Over several afternoons, Reyes recounted the 14-year journey that had brought her to Lafayette Square from the hot, agricultural province of Usulutan, where she and Ramon met and fell in love as teenagers. Ricardo was born in 1995, then Jose Ramon six years later. But their lives were shattered by violence when gangs threatened the family grocery business and shot Ramon’s brother dead.

Fearing for his life, Ramon fled to the United States and made his way to relatives in Virginia, where he applied for “temporary protected status” available to those fleeing war, violence and natural disasters in Central America. That status was made renewable every year, meaning that Ramon and can live and work in the U.S. indefinitely.

Soon, Reyes said, he began urging her to come north and join him. In 2004, she made the hazardous journey across Mexico and the U.S. border, bringing Ricardo but leaving 3-year-old Jose Ramon behind. The decision seemed prudent at the time, but it kept gnawing at her.

The family built a modest life in the Maryland suburbs, with Ramon able to work steadily as a janitor after he obtained refu­gee status. Rosario added income from part-time kitchen and babysitting jobs, but she had arrived too late to apply for the same legal protection. She lived cautiously, taking buses so as not to get caught driving illegally.

The couple often talked about trying to visit Jose Ramon or bringing him to the United States, but each time they decided it was too dangerous. Instead, as he grew older, they kept in touch by Skype.

“I help him with his homework, but I just want to have him with us as a family, especially at Christmas,” Reyes said.

But it was the chance to help Ricardo become legal, after 17 years in the United States, that drew Reyes to the immigrant cause. Like many other Latino parents in Maryland, she said she started attending events to demand protection for “dreamers” like him. That June, Obama signed an executive order offering “deferred deportation” for qualified illegal youths, and Ricardo’s application was approved.

Reyes, inspired by that experience, decided to participate in a “fast for families” on the Mall last November, organized by church, labor and immigrant groups to press the House to pass immigration reform. She dropped out after two days, but the hunger strike went on for three weeks, gaining nationwide attention.

This time, when local activists asked her to join a new fast asking Obama to take action on his own, she immediately said yes.

By Tuesday, after going without food for nine days, she had lost 14 pounds. Her back ached from sleeping in a wooden bunk at National City Christian Church. She said she was determined to keep going but worried about the coming cold and missed her family.

“When is Obama coming back from China?” Reyes asked, peering at the White House lit up in the dark across the stone plaza. “Do you think he’ll be able to see us?”

By Friday, the fast had collapsed — a casualty of hunger, descending wintry weather and squabbles among the strikers. But in a way, Reyes felt they had succeeded anyway, because the news was full of talk about Obama taking action soon.