Republican Sen. Marco Rubio of Florida, who has been working on an alternative version of the DREAM Act, criticized Obama for taking a piecemeal approach Friday. He said in a statement that "by once again ignoring the Constitution and going around Congress, this short-term policy will make it harder to find a balanced and responsible long-term one."

Rubio is considered a possible running mate for certain GOP presidential nominee Mitt Romney, who rejected the DREAM Act in the heat of the Republican primary campaign but has since expressed willingness to consider whatever Rubio proposes.

Later Friday, Romney told reporters that the issue needs more substantive action than an executive order, which can be replaced by a subsequent president.

He said he agrees with Rubio's statement that Obama's move makes finding a long-term solution more difficult. As president, Romney said, he would seek to provide "certainty and clarity for people who come into this country through no fault of their own by virtue of the actions of their parents."

Hispanics make up the fastest-growing immigrant population in the country, and the Latino vote is considered a crucial bloc for the November presidential election.

A spokeswoman for a major Latino group, the National Council of La Raza, hailed the administration's move.

"In light of the congressional inaction on immigration reform, this is the right step for the administration to take at this time," said NCLR spokeswoman Laura Vazquez.

Immigration lawyers also called the change a major step in the right direction. However, one immigration expert warned that the new policy does not guarantee the result sought by participants.

"I worry that the announcement will be implemented more stingily than the administration would like," said Stephen Yale-Loehr, who teaches immigration law at Cornell Law School.

Meanwhile, some evangelical Christian leaders who recently met at the White House to discuss immigration issues also endorsed Friday's move, along with the U.S. Council of Catholic Bishops and some Jewish groups.

For Jose Luis Zelaya, who came to the United States illegally from Honduras at age 14 to find his mother, also an illegal immigrant, the new policy means that "maybe I will be able to work without being afraid that someone may deport me."

"There is no fear anymore," he said.