Biden to Announce Broad Plan to Reverse Trump Immigration Policies

Ms. Praeli, a onetime undocumented immigrant from Peru who became a citizen in 2015, said that “11 million of us live and work every day.”

“We raise families in communities without any protection from deportation and family separation, vulnerable to exploitation and abuse in the workplace,” she added. “So it is long past time for real change.”

Ms. Praeli and other activists said they would demand that Mr. Biden reject attempts to water down his immigration proposals as he pushes the legislation through Congress.

“We need a clear and unapologetic intervention in the direction the country is going,” said Greisa Martinez, an undocumented immigrant who is the executive director of United We Dream, a group that has pushed to protect the Dreamers from deportation. “The time is done for compromises. The time is now for bold change. Our movement and our power are undeniable. Our demands are undeniable. We are ready.”

As described by transition officials, Mr. Biden’s legislation would profoundly reshape the American immigration system, making it more generous to current immigrants and people from other parts of the world while rejecting the anti-immigrant rhetoric that Mr. Trump sounded from the moment he became a presidential candidate in 2015.

And it will kick off a contentious new debate about how the United States should treat outsiders, an issue that has been at the center of the breach between the two parties for decades. While Democrats narrowly control both chambers of Congress, Mr. Biden will need bipartisan cooperation, especially in the Senate, where most legislation requires 60 votes. Because Democrats hold just 50 seats in the chamber, the new president will need 10 Republicans to support his efforts in order to pass it into law.

Mr. Obama successfully persuaded 68 senators, including 14 Republicans, to support a comprehensive immigration bill in 2013, only to have the effort die in the Republican-controlled House. Now, with Democrats in charge of the House, the challenge for Mr. Biden will be in the Senate, where almost all of the Republicans who backed Mr. Obama have left.