About 11.2 million illegal immigrants were living in the United States in 2010, a number essentially unchanged from the previous year, according to a report published Tuesday by the Pew Hispanic Center, a nonpartisan research organization in Washington.

Despite continuing high unemployment among American workers, record deportations by the Obama administration and expanding efforts by states to crack down on illegal immigrants, the number of them in the workforce about 8 million was also unchanged, the Pew report found.

The population of illegal immigrants has leveled off after it peaked in 2007 at 12 million, then dropped sharply over two years to 11.1 million in 2009, the report finds. The declines occurred primarily because many fewer people from Mexico and Central America came illegally to the United States, the Pew researchers concluded.

The report found no evidence of a significant exodus of illegal immigrants from the country. There was no sign that Mexicans, who make up the majority of illegal immigrants 58 percent are going home in larger numbers.

The Pew report indicates that the continuing high numbers of immigrants in the country without legal status are confounding enforcement strategies by the Obama administration and by lawmakers, mainly in state legislatures, who want a tougher crackdown to persuade illegal immigrants to leave.

Immigration authorities deported about 400,000 immigrants in each of the last two years, setting records, according to the Department of Homeland Security.

In all, immigrants from Mexico and other Latin American countries are 81 percent of all illegal immigrants.

The Pew report found that about 350,000 babies were born in 2009 to families with at least one illegal immigrant parent, a number that was also unchanged from the previous year. About two-thirds of the immigrant parents of those children had arrived in the United States before 2004, the report found. In all, about 4.5 million United States citizen children have at least one parent who is an illegal immigrant.

Republican lawmakers in state legislatures and in Congress have announced initiatives to cancel the automatic granting of United States citizenship for the children born here of illegal immigrants.

Nevada has the highest share of unauthorized immigrants in the workforce, about 10 percent, followed by California, where they are 9.7 percent.

In a highly contested race in Nevada, Senator Harry Reid, the majority leader, won re-election in November against a Republican, Sharron Angle, based largely on Hispanic votes. Mr. Reid had advocated an immigration overhaul to grant legal status to illegal immigrants.

Copyright 2011 The New York Times Company. Reprinted from The New York Times, National, of Tuesday, February 1, 2011.