“It just doesn’t seem rational that any political leader would say, let’s give millions of foreign workers permanent access to U.S. jobs when we have millions of Americans looking for jobs,” said Roy Beck, executive director of NumbersUSA, a group that favors reduced immigration. Mr. Beck predicted that Mr. Obama would face “an explosion” if he proceeded this year.

“It’s going to be, ‘You’re letting them keep that job, when I could have that job,’ ” he said.

In broad outlines, officials said, the Obama administration favors legislation that would bring illegal immigrants into the legal system by recognizing that they violated the law, and imposing fines and other penalties to fit the offense. The legislation would seek to prevent future illegal immigration by strengthening border enforcement and cracking down on employers who hire illegal immigrants, while creating a national system for verifying the legal immigration status of new workers.

But administration officials emphasized that many details remained to be debated.

'Politically disastrous'
Opponents of a legalization effort said that if the Obama administration maintained the enforcement pressure initiated by Mr. Bush, the recession would force many illegal immigrants to return home. Dan Stein, the president of the Federation for American Immigration Reform, said it would be “politically disastrous” for Mr. Obama to begin an immigration initiative at this time.

Anticipating opposition, Mr. Obama has sought to shift some of the political burden to advocates for immigrants, by encouraging them to build support among voters for when his proposal goes to Congress.

That is why Representative Luis V. Gutierrez, a Democrat from Mr. Obama’s hometown, Chicago, has been on the road most weekends since last December, traveling far outside his district to meetings in Hispanic churches, hoping to generate something like a civil rights movement in favor of broad immigration legislation.

Mr. Gutierrez was in Philadelphia on Saturday at the Iglesia Internacional, a big Hispanic evangelical church in a former warehouse, the 17th meeting in a tour that has included cities as far flung as Providence, R.I.; Atlanta; Miami; and San Francisco. Greeted with cheers and amens by a full house of about 350 people, Mr. Gutierrez, shifting fluidly between Spanish and English, called for immigration policies to preserve family unity, the strategic theme of his campaign.

Delays and setbacks
At each meeting, speakers from the community, mainly citizens, tell stories of loved ones who were deported or of delays and setbacks in the immigration system. Illegal immigrants have not been invited to speak.

Mr. Gutierrez’s meetings have all been held in churches, both evangelical and Roman Catholic, with clergy members from various denominations, including in several places Muslim imams. At one meeting in Chicago, Cardinal Francis George, president of the United States Conference of Catholic Bishops, officiated.

One speaker on Saturday, Jill Flores, said that her husband, Felix, an immigrant from Mexico who crossed the border illegally, had applied for legal status five years ago but had not been able to gain it even though she is an American citizen, as are their two children. Now, Ms. Flores said, she fears that her husband will have to leave for Mexico and will not be permitted to return for many years.

In an interview, Mr. Gutierrez rejected the idea that the timing is bad for an immigration debate. “There is never a wrong time for us,” he said. “Families are being divided and destroyed, and they need help now.”

Jeff Zeleny contributed reporting.

This story, "Obama to Push Immigration Bill Despite the Risks", originally appeared in The New York Times