The new operation will be overseen by Dana Remus, who has served as Mr. Biden’s general counsel on the 2020 campaign, and Bob Bauer, a former White House counsel during the Obama administration who joined the Biden campaign full-time over the summer as a senior adviser.

Inside the campaign, they are creating a “special litigation” unit, which will be led by Donald B. Verrilli Jr. and Walter Dellinger, two former solicitors general, who are joining the campaign. Hundreds of lawyers will be involved, including a team at the Democratic law firm Perkins Coie, led by Marc Elias, which will focus on the state-by-state fight over vote casting and counting rules. And Eric H. Holder Jr., the former attorney general in the Obama administration, will serve as something of a liaison between the campaign and the many independent groups involved in the legal fight over the election, which is already raging in the courts…

Ms. Remus and Mr. Bauer outlined a multipronged program that will include some elements common to past presidential campaigns, such as fighting off voter suppression and ensuring people understood how to vote, and some more unique to 2020, such as administering an election during a pandemic and guarding against foreign interference.

“There are,” Mr. Bauer said, “some unique challenges this year.”