Nathaly Uribe's grandmother broke into tears Friday when the Glen Burnie high school senior told her of a new federal policy that would protect many undocumented young immigrants from deportation.

"Now," the older woman said, "I know I can't lose you."

Like many young immigrants, Uribe, 17, has spent most of her life in the United States haunted by the specter of deportation. The native of Chile is an honors student at Glen Burnie High School with a passion for volunteering and dreams of a career as a genetic researcher. But the road ahead seemed treacherous before President Barack Obama announced his policy shift Friday, a move advocates say will affect as many as 800,000 people nationwide.

"One of the big questions was once I do get a college education, would I be able to work?" Uribe said Friday afternoon. "Now I can move ahead without fearing deportation." She said she spent the day calling other immigrant families, saying, "Now you're safe. You're OK."

Obama seemed to be speaking of immigrants like Uribe when he explained his decision.

"These are young people who study in our schools, they play in our neighborhoods, they're friends with our kids, they pledge allegiance to our flag," the president said during a Rose Garden address Friday. "They are Americans in their heart, in their minds, in every single way but one: on paper."

Uribe, who came to the U.S. at age 2, said, "This is my country. This where my loyalty is and where my love is. I would never want to go back to Chile."

Under Obama's proposal, illegal immigrants would be allowed to apply for a work permit if they were brought to the country before they turned 16 and have no criminal record. They must also be under 30 years old and either attend school, have graduated from high school or have served in the military.

State immigration activists said the new policy would complement the Maryland DREAM Act — up for referendum this fall — which would grant in-state college tuition to certain undocumented residents.

"This is huge news," said Kristin Ford, a spokeswoman for Educating Maryland Kids. "These children have worked hard, they've played by the rules, and the president is acknowledging that they have something to contribute to this country."

Ford said it's not clear how many Maryland residents will benefit from Obama's policy change, because it addresses a broader pool than those who would be eligible for in-state tuition under the Maryland legislation.

"This really clears up the issue of whether these kids can get jobs," she said. "It will allow them to work legally, so it clears up the question of what to do with these highly educated kids."

Several Maryland Democrats backed Obama's policy shift.

"The announcement today recognizes that we should not hold hardworking, innocent children responsible for the actions of their parents," said Sen. Ben Cardin, a Maryland Democrat who is up for re-election this year. "We should focus our immigration enforcement on the most dangerous individuals rather than children who mostly have known no other country than the U.S."

Sen.Barbara A. Mikulskiechoed his thoughts in a statement, saying, "Young people who were brought here as children should be able earn an education and serve their country without threat of deportation."

In a statement, Gov. Martin O'Malleyurged state voters to "build on this momentum" by supporting the DREAM Act. The new policy, O'Malley said, is a "very positive and important step for young people in our country who consider themselves Americans and deserve the opportunity to contribute to our country's future without the fear of enforcement action."

Maryland Rep.Roscoe G. Bartlett, a Republican who faces a difficult re-election this year, said the decision undermined the Constitution.

"President Obama's decisions will encourage more illegal immigration, weaken our border security and make it more difficult to have a bipartisan dialogue to reach consensus to fix our national immigration crisis," he said in a statement.

Rep. Andy Harris, the state's other Republican lawmaker, did not respond to requests for comment.

"How can the administration justify allowing illegal immigrants to work in the U.S. when millions of Americans are unemployed?" Rep. Lamar Smith, a Texas Republican and chairman of the House Judiciary Committee, said in a statement. "President Obama and his administration once again have put partisan politics and illegal immigrants ahead of the rule of law and the American people."