With a flurry of executive orders expected today, President Donald Trump's top advisers, including his incoming Department of Justice leadership, are preparing for a storm of legal challenges to some of the most controversial ones.

"We're going to get sued on all of these things," one top Trump adviser said, adding that the volume of litigation is expected to be a full-time job for Trump's DOJ.

Trump has privately told advisers that he believes flooding the zone with executive orders will lead to lawsuits that may be less effective given the volume of actions he plans to take.

During Trump's first administration, he faced upwards of 400 lawsuits challenging his actions. His advisers anticipate more than that this time.

There will be a team inside the Justice Department that is dedicated just to defending Trump's actions in court, sources said.

-ABC News’ Katherine Faulders

The transition from the Biden White House to the Trump White House is well underway and crews are working quickly to make the changes before Trump arrives later this afternoon, but the choices are nearly identical to his first term.

In the Oval Office, gold curtains have returned behind the Resolute Desk, as well as the red-and-beige carpet with green leaves that covered the wood floor.

As Trump sits at his desk, the portrait of President Andrew Jackson returned to the wall on his left side, just as it was during his first term. Biden had a portrait of Benjamin Franklin.

To Trump’s right, where Biden hung a 1917 flag-decorated Childe Hassam painting, President Abraham Lincoln is now back on display.

Other areas of the West Wing still need to be unboxed. In the Cabinet Room is a cardboard box with "DJT Office Bibles" written on the side.

-ABC News’ Justin Ryan Gomez

Members of Congress, officials joining the new administration and tech leaders including Meta CEO Mark Zuckerberg have congregated for an inauguration luncheon at the Capitol.

Sen. Amy Klobuchar, who chairs the Inaugural committee, is seated between Trump and Vance.

Former House Speaker Nancy Pelosi was critical of Trump's inaugural speech, pointing out that he didn't mention his plan to cut taxes on the wealthy.

"In the President’s first term, his only accomplishment was enacting tax cuts that gave eighty-three percent of the benefits to the top one percent while increasing the national debt by $2 trillion," she said in a statement.

"While he didn’t say it in his speech, the President campaigned on an extension of those tax cuts being his first priority in the new Congress," Pelosi said. "The American people want us to build an economy from the middle out -- not from the top down."

Pelosi's statement came as Trump slammed the former speaker in remarks to his supporters at Emancipation Hall.

"She's guilty as hell," Trump said of Pelosi over her response to the attack on the U.S. Capitol.