The new Obama administration policy, known as Deferred Action for Childhood Arrivals, makes undocumented immigrants younger than 31 as of June 15, who came to the United States before age 16, eligible for two-year renewable work permits and a reprieve from possible deportation -- if they meet certain requirements previously proposed under the Dream Act.
The Dream Act, stalled in Congress, would provide conditional permanent residency to certain undocumented immigrants of good moral character with no criminal record, who graduated from U.S. high schools or served in the U.S. armed forces, lived in the United States continuously for at least five years before the bill's enactment, among other criteria.
Application forms explaining the criteria were posted on the U.S. Citizenship and Immigration Services Web site at uscis.gov/childhoodarrivals, a United Press International review indicated.
USCIS Director Alejandro Mayorkas, who was born in Havana and moved to the United States at age 1, said application requests would likely take "several months to process."
Applicants -- who must also prove they financially need work and are in school or a job-training program.-- may follow the progress of their application online, he said.
USCIS, which will review the applications, said it expected about 1.2 million applications on top of the 6 million applications it normally adjudicates for citizenship, residency and work visas every year.
Some advocacy groups estimated more than 1.7 million undocumented children and young adults may be eligible.
Those groups planned public celebrations, legal-aid seminars and other events in major cities Wednesday to herald the program.
By contrast, Republicans, who have generally opposed measures to benefit undocumented immigrants, said the policy change is a White House ploy for Latino support in an election year and a backdoor amnesty that usurps congressional authority.
When he unveiled the plan June 15, President Barack Obama said his order, which bypassed Congress, did not offer amnesty or immunity, and did not create a path to citizenship for undocumented immigrants.
He called it "a temporary stopgap measure" because Congress had failed to act.
Rep. Lamar Smith, R-Texas, denounced the policy Tuesday as a "magnet for fraud and abuse" designed to win votes for Obama.
"There seems to be little if any mechanism in place for vetting fraudulent applications and documentation submitted by illegal immigrants," Smith said in a statement.
He claimed the application process was free for applicants, so taxpayers would have to foot the bill.
USCIS, part of the Department of Homeland Security, said the program includes a thorough fraud-detection unit, with stiff penalties for would-be scammers, as well as a mandatory $465-per-application fee so the program will fund itself.
The agency said it would deport and may prosecute applicants with felony records.
Smith said the immigration shift was a job killer that could cost Obama the election.
"President Obama and his administration routinely put partisan politics and illegal immigrants ahead of the rule of law and the American people," Smith's statement said. "With this track record, it's looking more likely that even President Obama may lose his job in this economy when Americans go to the polls this November."
Rep. Steve King, R-Iowa, a member of the congressional Tea Party Caucus, promised to sue the administration over the changes.
Some activists worried a future president could overturn Obama's order, the Los Angeles Times said. They also feared undocumented immigrants who came out of the shadows and turned over their paperwork had no guarantees they would not be deported if their applications were rejected.