The White House clashed with the House Intelligence Committee on Tuesday over testimony from President Trump's former chief strategist Stephen K. Bannon, a dispute that could alter the course of congressional investigations into Russian interference in the 2016 presidential election.
Bannon, who was ousted from the White House in August and recently had an acrimonious falling out with Trump, was directed by the White House to avoid answering questions about the presidential transition or his work in the administration, according to committee members who were left frustrated by the daylong closed-door hearing.
Even conversations with the president after Bannon left the administration and returned to running the right-wing website Breitbart News could be subject to executive privilege, the committee was told by Bannon's lawyer.
Rep. Adam B. Schiff of Burbank, the panel's top Democrat, told reporters that the White House's stance was "completely unsustainable." Republican lawmakers appeared to agree.
Republicans and Democrats served Bannon a subpoena during the hearing, a much more aggressive step than the committee has previously taken when faced with witnesses who declined to answer questions.
But the subpoena did not spur the cooperation that the committee wanted.
Large portions of the hearing were spent arguing how the White House claim of executive privilege could apply to Bannon's testimony. Lawmakers said they expected to bring him back despite spending about 10 hours behind closed doors with him.
White House Press Secretary Sarah Huckabee Sanders declined to say whether Trump administration officials had asked Bannon to claim executive privilege to protect confidentiality in the White House.
"Congress must consult with the White House prior to obtaining confidential material," she said, reading from a statement. "This is part of a judicially recognized process."
The House Intelligence Committee has been split along partisan lines in recent months, with Democrats repeatedly criticizing their Republican colleagues as failing to more aggressively investigate the 2016 campaign.
But Tuesday brought a rare spirit of bipartisanship, and members of both parties were displeased.
"There are questions that we asked that were not answered," said Rep. Michael K. Conaway, a Texas Republican who is leading the Russia investigation. "We are going to get the answers from Mr. Bannon."
Bannon helped guide Trump's upset victory in the 2016 campaign and then joined his administration to help remake U.S. politics from inside the White House. But he was ousted in August, and his relationship with the president unraveled this month after the publication of "Fire and Fury," a book about Trump's first year in office.
Bannon's next step could be even more significant. He has been subpoenaed to appear before the criminal grand jury working with special counsel Robert S. Mueller III to determine whether the Trump campaign assisted the Russian intelligence operation, according to the New York Times.
Bannon confirmed to the committee that he has received a subpoena from Mueller, according to a source with knowledge of the conversation who requested anonymity to discuss private testimony.
The president's former senior advisor could provide new details under oath about conversations and meetings inside the Trump campaign and White House at crucial moments, as well as his claims in "Fire and Fury" that Mueller's investigation would be "all about money laundering."
Four former Trump aides, including his former campaign manager, Paul Manafort, and his former national security advisor, Michael Flynn, already have faced criminal charges. Manafort has pleaded not guilty to fraud, conspiracy and money laundering, and Flynn pleaded guilty to lying to the FBI.
A lawyer for Bannon did not respond to a request for comment Tuesday, and a spokesman for Mueller declined comment on the reported subpoena.
Like his tenure in the White House, Bannon's appearance on Capitol Hill was not short on drama.
Rep. Tom Rooney, a Florida Republican and a member of the panel, said during a break that disagreements about whether executive privilege could prevent Bannon from answering some questions were "sort of dominating the day."
Mieke Eoyang, a former committee staff member now at Third Way, a Washington think tank, said subpoenas were sometimes used when lawmakers' questions are met with hostility.
"They really don't like it when the witness treats them with contempt," she said. "Everything about Bannon's personality suggests that he wouldn't show the kind of deference and respect that the committee would want from a witness."
Bannon's testimony has been anticipated since the book "Fire and Fury: Inside the Trump White House," by Michael Wolff, hit the headlines and the bestseller lists this month.
Among other surprises, the book quotes Bannon denouncing a controversial meeting between a Kremlin-linked Russian lawyer and her entourage with three top campaign officials at Trump Tower in June 2016 as "treasonous."
"Even if you thought that this was not treasonous, or unpatriotic, or bad … and I happen to think it's all of that, you should have called the FBI immediately," Bannon is quoted as saying.
Bannon later backpedaled by saying he was not aiming his barb at Donald Trump Jr., the president's eldest son, who said he had arranged the meeting because he expected the Russians to provide damaging material on Hillary Clinton. Manafort and Jared Kushner, Trump's son-in-law and advisor, also attended.
But Bannon's harsh comments destroyed what was left of his once-close relationship with Trump, who issued a statement saying his former advisor had "lost his mind" when he was forced out of the White House last summer.
The fallout also cost Bannon his job running Breitbart News after his support from major political donors evaporated.
Corey Lewandowski, another former Trump campaign manager, is scheduled to testify to the panel behind closed doors on Wednesday, according to a source who was not authorized to speak publicly.
Hope Hicks, the White House communications director and a close confidante of the president, also is expected to appear before the panel as soon as this week.
She is likely to be questioned about her role in helping the president craft a misleading response on Air Force One about the June 2016 meeting between the Russian lawyer and the three top campaign officials.
Committee Chairman Devin Nunes, a Republican from Tulare, was forced to step back from the Russia inquiry during a controversy last year over how he handled classified information.
An ethics committee investigation later cleared him of wrongdoing, and Nunes has aggressively pursued his own lines of inquiry, examining whether the Department of Justice improperly investigated the Trump campaign.
6:35 p.m.: The article was updated with details of the arguments over executive privilege in the House hearing.
3:55 p.m.: The article was updated with reports that Bannon has been subpoenaed to appear before a criminal grand jury and other details.