Former White House communications director Hope Hicks testified Wednesday before the House Judiciary Committee in a closed-door hearing for nearly seven hours. She did not talk about anything that took place during her tenure at the White House, one Democrat in the hearing told reporters.

When Rep. Ted Lieu, a California Democrat, walked out of the hearing earlier in the day, he said, "I'm watching obstruction of justice in action."

"The White House lawyers are exerting 'absolute immunity,' which is not a thing, it doesn't exist...about anything pertaining to her time in the White House," Lieu complained. He said that Hicks would not answer a question "as simple as, 'where was your office located?' 'Objection.' It's ridiculous," Lieu said. There's no such thing as absolute immunity."

Get Breaking News Delivered to Your Inbox

Hicks was instructed by the president not to answer any questions on the period of time when she was working for the White House. She was, however, allowed speak about her time on the Trump campaign. Lieu confirmed that she was answering questions about that period of time.

The Judiciary Committee's ranking member, Rep. Doug Collins, of Georgia, dismissed the hearing as a "political stunt," and said the committee learned nothing new from Hicks.

Rep. Sheila Jackson Lee, Democrat of Texas, called Hicks' testimony a "building block" in determining the committee's next steps in its investigation into whether the Trump administration engaged in obstructive conduct. She said that Hicks "reinforced" some of the areas the committee is looking into, alluding to hush money payments coordinated by former Trump fixer Michael Cohen for a woman who claimed she had an affair with Mr. Trump over a decade ago.

But Hicks is just "one peg" in the board, Jackson Lee told reporters outside the hearing room, and the committee would also "need to proceed" with former special counsel Robert Mueller and former White House counsel Don McGahn.

Rep. Madeleine Dean, of Pennsylvania, told reporters that she asked Hicks about her 2016 comments that there were no contacts with Russians during the campaign. When pressed, she said Hicks told the panel there had been some emails and interview requests but she did not consider those contacts. She also predicted this would be a test case in court of the administrations claims of immunity.

The White House had a lawyer present during the hearing to assert executive privilege on some of the information Democrats wanted from Hicks, a Democratic aide said. White House Counsel Pat Cipollone maintained to House Judiciary Committee Chairman Jerry Nadler, Democrat of New York, that Hicks is immune from testifying about her time as senior White House adviser.

Democrats on the committee wanted to press Hicks on the hush money payments President Trump's former personal attorney Michael Cohen made to adult film actress Stormy Daniels and key moments during the Russia investigation, a Democratic committee aide told CBS News.

Lawmakers also wanted to ask Hicks about former national security adviser Michael Flynn's ouster, the president's decision to fire FBI Director James Comey, his efforts to thwart special counsel Robert Mueller's nearly two-year investigation and a meeting at Trump Tower in the summer of 2016 that included Mr. Trump's son, Donald Trump, Jr., top campaign officials and a Russian lawyer Trump Jr. thought had damaging information about Hillary Clinton.

Hicks left the White House in March 2018. Before her roles as director of communications and strategic communications, she was the national press secretary for Mr. Trump's presidential transition team and his top spokeswoman during the 2016 campaign.

Earlier this month, Cipollone directed Hicks not to hand over documents to the committee related to her time in the White House in response to a subpoena from the Judiciary Committee. She did turn over some documents from her time with the Trump campaign.

Nancy Cordes contributed to this report.