WASHINGTON — The White House on Monday blocked two more former aides to President Trump from testifying in House Democrats’ impeachment inquiry, but cleared a third witness, Corey Lewandowski, to appear publicly on Tuesday and answer limited questions about potential obstruction of justice by the president.
The White House decisions amounted to mixed news for the House Judiciary Committee as it tries to crank up the intensity of an investigation devised to determine whether to recommend Mr. Trump’s impeachment for obstruction of justice and abuse of power — and to convince the public that such action is warranted.
In Mr. Lewandowski, who managed Mr. Trump’s presidential campaign and remained a confidant once he became president, the judiciary panel will be getting a figure who could help bring to life evidence uncovered by Robert S. Mueller III, the special counsel who investigated Russia’s interference in the 2016 election. Though the panel has publicly quizzed legal experts and Mr. Mueller on his findings, Mr. Lewandowski will be the first fact witness referenced in Mr. Mueller’s report whom the White House has not blocked from publicly testifying entirely.
He played an important role in an attempt by the president in summer 2017 to effectively end scrutiny of Mr. Trump’s campaign, one of several episodes that Democrats have said were clear cases of obstruction. But Mr. Lewandowski is also pugnacious, fiercely loyal to Mr. Trump and contemplating a Senate run in New Hampshire — and he has pledged to “fight back” against the Democrats.
“I am an open book,” he said in August in a Fox News Radio interview. “I want to go and remind the American people that these guys are on a witch hunt.”
The White House ordered two other former aides to Mr. Trump, Rob Porter and Rick A. Dearborn, not to appear before the Judiciary Committee, a move that will only compound a fight playing out in the courts over whether Mr. Trump can continue to effectively stonewall attempts by Congress to investigate his administration, including by refusing to allow current and former officials to testify.
The White House counsel, Pat A. Cipollone, wrote to the committee late Monday, saying that Mr. Lewandowski would be free to discuss his work on the Trump campaign and matters that have already been made public by Mr. Mueller, but not any other additional communications he may have had with Mr. Trump after the election. As senior White House aides, Mr. Porter and Mr. Dearborn were “absolutely immune” from congressional testimony, he said in another letter.
“In light of the long-settled principles discussed above, and in order to protect the prerogatives of the office of president, the White House has directed Mr. Lewandowski not to discuss the substance of any conversations he had with the president or senior presidential advisers about official government matters, unless the information is expressly contained in the report,” Mr. Cipollone wrote.
Representative Jerrold Nadler, Democrat of New York and the chairman of the Judiciary Committee, promptly rejected the claims as “a shocking and dangerous assertion of executive privilege and absolute immunity.”
“If he were to prevail in this cover-up while the Judiciary Committee is considering whether to recommend articles of impeachment,” Mr. Nadler said of the president, “he would upend the separation of powers as envisioned by our founders.”
Democrats do not recognize any legitimate constraints of Mr. Lewandowski’s testimony because he never worked in the White House, potentially foreshadowing a fight on Tuesday over what he can and cannot say.
And the House has already initiated a lawsuit in federal court challenging the long-held executive branch position that senior presidential aides have “absolute immunity” from congressional subpoenas. Though that suit is nominally intended to free up the testimony of Donald F. McGahn II, the former White House counsel and perhaps the most important obstruction-related witness, a ruling in the committee’s favor could force the White House to let other aides, like Mr. Porter and Mr. Dearborn, testify as well.
Tuesday’s hearing is shaping up to be an important test for Democrats as they struggle to engage and retain the public’s attention with what they argue is ample evidence of impeachable conduct. Democrats’ increasingly muddled messaging on impeachment has not helped, as party leaders and liberal lawmakers have publicly disagreed over whether a meaningful impeachment inquiry is underway.
Mr. Nadler sought earlier Monday to clear up lingering questions about the seriousness of his panel’s work.
“Personally, I think the president ought to be impeached,” Mr. Nadler said during an interview on WNYC. But, he conceded, the House was still divided on that point and would not advance impeachment articles unless it could win over public support.
“The American people have to be educated and they have to be convinced,” he said. “We cannot impeach the president against the will of the American people.”
To that end, Democrats are likely to use most of their questioning on Tuesday to spotlight a scheme in which the president enlisted Mr. Lewandowski to try to curtail the special counsel investigation, one of 10 possible acts of obstruction detailed by Mr. Mueller. They may also ask Mr. Lewandowski about his knowledge of the Trump campaign’s contacts with Russians.
The attempts to influence Mr. Mueller’s work occurred in June and July 2017, not long after Mr. Trump ordered Mr. McGahn to fire Mr. Mueller, a command he refused.
In this case, the report says the president “dictated a message” to Mr. Lewandowski that he wanted him to deliver to Jeff Sessions, the attorney general. The message instructed Mr. Sessions, who was recused from the matter, to state publicly that the special counsel’s investigation was “very unfair,” and then to significantly narrow its scope to prevent future interference, effectively ending the investigators’ scrutiny of Mr. Trump’s campaign.
Mr. Trump followed up about a month later, and Mr. Lewandowski indicated he would deliver the message. He did not, however, and instead asked Mr. Dearborn, a former aide to Mr. Sessions then working in the White House, to do so instead. Mr. Dearborn, too, was uneasy about the request, and Mr. Mueller wrote that he never delivered it.
Because of a Justice Department policy that prohibits charging a sitting president, Mr. Mueller ultimately did not decide one way or another whether Mr. Trump’s actions amounted to criminal obstruction of justice.
While Mr. Porter was not directly involved in the president’s efforts to limit the scope of Mr. Mueller’s work, his job put him in proximity to Mr. Trump and made him aware of the flow of information coming in and out of the Oval Office. As staff secretary, Mr. Porter’s notes from the White House are frequently referenced in Mr. Mueller’s report, and he was wrapped up in the president’s attempts to get Mr. McGahn to falsely deny that he had ordered him to fire Mr. Mueller after The New York Times revealed the episode.
Mr. Trump, for his part, continues to rail against congressional investigators, whose work he has portrayed as a desperate attempt to take him down. On Monday, he wrote on Twitter that Democrats had “given up” on the findings of the Mueller report, were hunting through “everything else” about him to try to make their case and should instead look at lucrative book and television deals signed by his predecessor Barack Obama and other Democrats.
As Tuesday’s hearing was expected to demonstrate, Democrats continue to see Mr. Mueller’s findings as a central part of their impeachment investigation. But they have begun broadening their scope this fall in an effort to evaluate the severity of other potential offenses.
The committee has set an additional deadline for Tuesday one of those other areas of scrutiny: reports that Mr. Trump has dangled pardons to immigration officials willing to carry out his policies at the border even if they break the law. Homeland security officials are under subpoena to hand over documents relevant to several reported episodes, which Mr. Trump has denied.