After The Times contacted the White House about the situation, Mr. McGahn privately erupted at Mr. Cobb, according to people informed about the confrontation who asked not to be named describing internal matters. John F. Kelly, the White House chief of staff, sharply reprimanded Mr. Cobb for his indiscretion, the people said.
Mr. Cobb sought to defuse the conflict in an interview over the weekend, praising Mr. McGahn as a superb lawyer. “He has been very helpful to me, and whenever we have differences of opinion, we have been able to work them out professionally and reach consensus,” Mr. Cobb said. “We have different roles. He has a much fuller plate. But we’re both devoted to this White House and getting as much done on behalf of the presidency as possible.”
The special counsel, Robert S. Mueller III, is investigating connections between Russia and Mr. Trump and his associates, including whether they conspired to influence last year’s election. Mr. Mueller is also looking into whether Mr. Trump’s decision to fire James B. Comey, the F.B.I. director initially leading the investigation, constitutes obstruction of justice. He has asked the White House for emails and documents related to these matters, and Mr. Cobb has organized the requests into 13 categories, but officials would not describe them in more detail. So far, officials said the White House has not turned down any request.
Mr. Trump’s aides said they were scrambling to respond to the requests to avoid a subpoena that might make it look as if the White House was not cooperating. Mr. Cobb hoped to turn over a trove of documents this week, according to people close to the legal team.
Mr. Cobb argues that the best strategy is to be as forthcoming as possible, even erring on the side of inclusion when it comes to producing documents, because he maintains the evidence will show Mr. Trump did nothing wrong. Mr. McGahn has told colleagues that he is concerned that Mr. Cobb’s liberal approach could limit any later assertion of executive privilege. He has also blamed Mr. Cobb for the slow collection of documents.
Complicating the situation is that Mr. McGahn himself is a likely witness. Mr. Mueller wants to interview him about Mr. Comey’s dismissal and the White House’s handling of questions about a June 2016 meeting between Donald Trump Jr. and a Russian lawyer said to be offering incriminating information about Hillary Clinton.
Mr. McGahn is willing to meet with investigators…